Bitcoin Forum

BTC was created with a new transaction system without a central authority. The BTC can be used in the future as the main currency that we gonna pay with. But what's gonna be the value of a main currency? What's the value of dollars or eur?

-Answer is: The dollar IS the value. The dollar doesn't cost anything. The dollar is the value.

If BTC is gonna be used in future, it not gonna cost anything, because the BTC is gonna be the value. It not gonna be like Bitcoin cost 50,000dollars... Bitcoin not gonna cost anything because Bitcoin IS the value. But that's probably not gonna happen. We not gonna pay with BTC but with stable coins like USDT...

Not sure where you get the idea that bitcoin can and will become the main currency in the future, because I doubt that it will happen. But in any case it will, I have no idea what will be the value of bitcoin, it still depends on the basic economic concept of law of supply and demand. Again, will the government allow bitcoin to be the main currency though, and we all know the answer for that one, they won't simply let that happen to their USD, and there's no way that any crypto will be for that matter.

I agree with you. And I personally think that if there would be a main currency, that would be something that can be controlled by the government for sure. But in hypothetical manner, I wouldn’t also have an idea as to what will be the value of bitcoin, if it were to be the main currency then. Maybe we’ll just know when we get there, if we ever get there.

That's what i was thinking about bitcoin adaption. If the government has no control over bitcoin, it will never allow it to become the major crypto currency of the world. And if the government has control over it, they will definitely control its price somehow.

In an ideal world, if bitcoin becomes the main currency and is used by every individual of the world, then for sure it price will be more than 10 million dollars or even more.


 

The value of money is expressed through its purchasing power, which in turn is expressed in the number of real goods that you can buy with money. If a loaf of bread costs one dollar, that means the value of one dollar would be one loaf of bread. The dollar itself doesn't have an intrinsic value, it is not used for industrial purposes like gold is, so the only use case of the dollar is as a medium of exchange. Similarly, bitcoin doesn't have any additional use cases besides the medium of exchange, but it is superior to both gold and the dollar because it combines the soundness of gold and the transportability of the dollar. People that appreciate this superiority of bitcoin are willingly accepting it in exchange for services and goods. That is why bitcoin has value.

Except that bitcoin being the "main" currency doesn't automatically mean there will not be alternatives. Because what are the chances that bitcoin will be the only existing currency? Near-zero that you might as well say that it's impossible.

If Bitcoin will be the main currency, it's value should be pegged into something that has a stable value and not the typical skyrocket price that everyone here will assume. There's no way too that a decentralized currency will gonna be used by the government since they don't any protection to it's economy once someone try to manipulate the market unlike fiat that has an infinite supply and regulated properly by the government.

It took me 3x reading this thread to draw any conclusions and what the content of the message was that the OP wanted to convey. IMO, Bitcoin would have no value if there were no Dollars (for now). Because the OP said that in the future Bitcoin is expected to be the main currency, of course, it refers to the value that is in Bitcoin, not to the value that is currently converted to Dollars.
Who will control the authority of Bitcoin if later the value applied to payments is no longer Dollars? but rather Bitcoin itself. Because everything can not be predicted, even we ourselves are not 100% sure that makes Bitcoin the single main currency of the world. Given that there is no guarantee or measure of its value.

Stable coins are only good for trading.
The reason why someone might not be using normal USD and using stable coins like usdt instead of just paying in general currency is weird. They can very easily use the pegged currency. Rest if bitcoin was the main currency then it would be acting much like other major fiat currencies, like dollars or Euros. Plus it would also be less volatile, the volatility would increase in the first session when the currency would be widely accepted but slowly it would decrease and become constant to cater to the need since a currency should be : widely accepted and non volatile to fill roles of fiat worldwide.

Actually, we can estimate the value of dollar and other fiat money as well. First of all, the value of currency can be taken as the value of economy of the country that releases this currency. One more thing of how we can estimate their value is to think about how much we can buy for one unit. As bitcoin is the global currency, we would not be able to think about it like value of economy of one country so we would estimate it based on how much we can buy on one BTC

Dollar has exchange rate between it and other currencies. Also dollar's value is changing, and economists use various methods to calculate this change. There is not a single thing in this world that has a fixed value, because value in market economy is subjective and unstable. Just because people like to measure everything in dollars, doesn't mean that dollar is vastly different from other currencies. So if Bitcoin replaced the US dollar, it would still have a price in US dollar and other fiat currencies.

if there was no dollar/other fiat to exchange to value it against. then it reverts to a barter system. where some can compare it to bottles of vodka, or a hour of minimum wage units or some other nationally recognised medium of exchange.

EG if people traded their time and valued it in how many loaves of bread they can buy per hour.
then right now bitcoins value would be about 30,000 loaves of bread

bread is a bad example as different regions value bread at different labour value, but you get the idea.

some may say that the value could be more refined to something everyone pays equally. such as electric. so bitcoin could be valued at 126060kwh/btc

BTC will continue to be traded with the dominant currency pairs, so it will be reflected as BTC/USD, BTC/GBP, BTC/EUR, BTC/JPY, etc. BTC will also be traded with other cryptocurrencies, just as it is now. As its use increases, its price will of course increase relative to fiat currencies.

People should stop thinking that fiat currencies will go away, because they will also always have some utility, especially for governments. Cryptos and fiat can coexist.

That's just a big what-if though, in the first place I don't think Bitcoin would become the main currency, it was never made to be one in the first place. It was an alternative to the current fiat system afaik, only an alternative and nothing more.  And if Bitcoin were to become the main currency, then wouldn't most stuff revert to the system of the past? Cause honestly with the fiat, we at least have a centralized measure for the values of items and services. Without it though, it's like we're going back to what we were using back in the past, exchanges between merchants that are completely dependent on supply and demand.

your belief does not even have the right to happen . Bitcoin gonna be a Main Currency ? lol this will never come because Fiat will never leave and bitcoin will stay with fiat for lifetime
so the argument you are pointing wont even get close to the reality.

Dont worry Bitcoin value will be determined when the adoption happens , when majority of the country uses and accepted this then that will be the deciding factor if how and why will bitcoin be accepted in payments for daily purpose .

That is never going to happen in a million years.

Centralized altcoins like USDT will be immediately removed from existence by United States if they were used for payment instead of USD simply because they would be printing US dollar which is considered a threat to US and that threat will be eliminated immediately by the government. Since they are centralized, it is a very easy thing to do.

Additionally if people wanted digital dollar, they are already using digital dollar using their digital wallets, paypal, credit cards,.... there is no reason to use a centralized super risky shitcoin.

This is why this talk about Bitcoin will be the main currency of exchange someday is still dicy. Every other commodity or some sought of an asset today is still valued based on fiat USD. GOLD, SILVER, etc are all valued in USD and so is BTC, so you get where I am going. USD is the value of every other thing and once you remove the value, the thing becomes worthless. Bitcoin and other cryptos might be used for exchange or purchase but I don't think it will ever be the main currency.

There are no current exist cryptocurrencies that could replace USD as a global payment, and if there is someday i'm sure it's hard to replace it because the power of the people who controlled the paper fiat money is too strong, they already ruled this world for many generations so i think it's quite imposibble to create an environment where everything is paid by cryptocurrency.

Keep in mind that there is a big difference between widespread usage and replacing.
I have always said that bitcoin is never going to replace fiat and it wasn't designed to do that either but I also believe that there will come a day when bitcoin can be used anywhere in the world. For example tourists would no longer need to exchange their fiat to their destination country's currency, they would just use bitcoin when travel.

Yes, I do believe also that bitcoin will not be going and never going to replace fiat currency instead it will be one of the circulating currencies all over the world provided that many countries will be going to adopt crypto as a legal tender. Actually, I don't have any idea yet what would be the value of bitcoin once it is like for example used for any transactions like pay for a set of flights but if ever this would be going to happen I know it would be a breakthrough to a crypto platform and will be going to make the price or value of the bitcoin soar high.

That being said, this is one of the many factors why bitcoin as a main currency is close to being impossible to happen, because the government do not see it as controllable entity which makes it not ideal for them. And just like what you have said, if bitcoin would be a main currency then it can lose its features that we all loved since it will be certainly controlled by the government to align their ways and the system.

bitcoin will be the main currency in the virtual world not in the real world, and that's the rule, because the value of bitcoin is difficult to read if you don't use fiat, the value of bitcoin is only 1 and the smallest fraction of shatosi, in contrast to fiat which has value.
if you ask how much is the value of BTC in dollar or eur value? my answer is btc only 1 BTC can not be measured by usd or eur if you expect BTC to be your main currency

Until a few years ago even I used to think that bitcoin is going to be the future currency and people will use bitcoin for payments.
But I don't think that it will become a mainstream currency. People are adopting it more as a store of value as they consider it to be more precious to spend.
So I think that although bitcoin was mean to be a P2P payment mechanism it will be more used as a store of value and there will be other alternative coins for the payments.
There are coins which are faster and less cheaper than bitcoin which can be used for payments but we can't really be sure which one of them will be used mainstream.

i still believe they can be an option and i think an option is better than being the main payout.
there will be a lot of problems when they are used as the main payment tool, one of which is that the government is overheating because they certainly won't be able to regulate bitcoin easily :D
On the other hand, they also don't need that, what they need is only recognition regardless of whether it is used as a legal tender or not, it is a continuation after the acknowledgment.

If BTC was the main currency then it will not have fiat value, one btc will remain so without any market volatility because BTC is pegged to fiat people only see the fiat value of BTC but once this is removed people will then see BTC as it is, however, this can only happen with the approval of the government and we all know the stand of majority of the government of each country.

Bitcoin will always be viewed as a store of value, but its theoretical role as the global medium of exchange is just that, theoretical. I have mentioned several times on this forum that government bodies would never allow their future CBDC to not be on the menu. It's important to remember that bitcoin also has a long way to go development-wise before it can even dream of taking on that role and the volume of transactions that come with it.

Exactly! And I don't think Bitcoin will ever replace fiat in some country although El Salvador is different but for some country like developing countries, I don't think they would be happy to choose Bitcoin over fiat since the total circulation of Bitcoin is just too small if you compare to the total circulation of fiat.

Just like what you said, if we removed fiat, Bitcoin approach will be different in some people since they have known of using fiat with ease since the first day. It would feel weird to them using computer or phone all the time just to pay something but if there would be a credit or debit kind of crypto card maybe that hassle of using phone to pay something in digital way would be a lot easier.

We might consider Bitcoin as a legal tender in the future but I'm in doubt about thinking and considering it as the main currency. I'm certainly out of this. But what I'm expecting to happen in the future is that Bitcoin will remain the most profitable investment rather than being used as a currency to make purchases. As people will see being fit as an investment, they will keep doing this forever.
But talking about the value of BTC, it was unpredictable. It changes very often and even IF given the chance to be considered as THE MAIN Currency, I think it was very expensive than of today.

I recall many people back then asking that same thing. Widespread where they put it almost synonymous to replacing.
I just think of it like a credit cards from banks. That's how I see it at least in my country, not many uses it, but it is an alternative and could potentially be used by many merchants out here. There's almost a gray line between buying stuffs here through Bitcoin, though it still uses the local currency.

Me too. Not really sure whether BTC can be the main currency or not. I only expect BTC can be used in more countries as a currency (payment tool). Although in the future people may be more familiar with the internet and prefer buying online, we don't know if BTC can be the main option to pay for all the stuff or services.

Why are you so confident the price of BTC can be more expensive once it becomes the main currency?
Remember that it is not about BTC to be the main asset in the world, but to be the main currency. I think there will be a different situation here.

Not sure what you mean here. First of all, what does "main currency" mean? Bitcoin is a currency. Primary or secondary, doesn't matter. Bitcoin won't be replacing fiat anytime soon. Both fiat and bitcoin (including other crypto currencies) will be used along side with fiat currency. Are you trying to say that 1 bitcoin = 1 bitcoin? Yeah, this is what we want, but right now that is impossible. The market is very volatile and for our convenience we have to measure the value using fiat or stable currencies. Maybe in the future a cup of coffee will cost half a satoshi, but for now its going to cost around $2.

It would be difficult if not impossible if Bitcoin became the main currency. Such a fluctuating value will continue in the future, but I also don't know how exactly. Bitcoin is difficult to predict even though a professional even their predictions are sometimes still wrong. Even if Bitcoin becomes the main currency, no one knows what its value will be, whether it will remain volatile or not and how much its value will still be high or even down. But for me personally, Bitcoin is more suitable as an investment because it is more promising.

You have a point. And I think that we, bitcoin enthusiasts, would be the happiest if it were to be an option, right? Although, I doubt that bitcoin would come top of their list since you already mentioned that they will probably have problems regulating it. Nevertheless, you are right that the acknowledgment is a big factor in pushing this through, if it were to really happen.

I don’t think Bitcoin being the “main” currency could happen and it’s impossible in my opinion because of the price’s volatility and unpredictability. Fiat is still going to be the main currency and it will not go anywhere because the banks would remain for a very long time. Both fiat and crypto can coexist because they have different use cases.

I guess it's possible bitcoin will become a major currency although no one knows when it will. if that happens, I don't think the fluctuation will be this big where whales can manipulate the market. we know that until now only 5% of the world's population uses bitcoin, if everyone uses it, of course fluctuations will be like the current forex market

If it's the main currency then it's going to have a cost and the same as its value. Although in the past, I've always believed that bitcoin can kick and replace the traditional fiat system and it's going to be the main currency of all, I think we're still far from seeing that into reality.
But I disagree at the last part, we're paying with bitcoin, we're using bitcoin just as the fiat, dollar, stable coins and any other medium of exchange because it's the main purpose of bitcoin.

Certainly, if it will going to happen somewhere in the future, the value of bitcoin stays the same and will not follow the value of any fiat because as @pearl12 said, bitcoin is pegged to fiat and not the other way around.

But on other hand, I'd still definitely doubt that it will be the case and that countries/governments will likely allow Bitcoin to be their main currency. And on the first place, its market is too volatile to make it as a main and second, definitely they won't allow that to happen as bitcoin is fully decentralized already and local fiats will still exists as it's still backed by the government itself.

We can't add a price to something with Satoshi yet without knowing the value of it by USD. There has to be a value in USD or fiat before we can add value in BTC. There is no way we can do that today and we may never do that because today the development is already moving to digital fiat which means there is still going to be fiat money, making BTC not the main currency.

If we could just sell a piece of land for 1BTC regardless of how big the land is, that's what makes it the main currency however that's now anyone would want.

Its true that btc is a virtual currency but it has a really value ,No one can ignore it .I just want to explain it on different way that if it is count as a shatoshi still it has a value .We are using paper currency but on banking system it still count as a digit like shatoshi .I think it will be the huge point for it tell as a currency .We can use it as a currency but the point is that the volatility of the market .If it goes down we will be very thoughtful for that to make plan how we will use it .There is not more thing concern on it we can really make transaction and exchange like euro and USD on btc so nothing more are there as well .On the hand to use btc government will need to make new rules and regulation so that the things is tough a bit but i think it is really possible to use as a main currency .

If bitcoin will be the main currency then BTC value will be high and it's price will touch to moon. And all bitcoin investors will be millinoers to billioners. And there will the big change come in cryoto market.

very true, at least even if they are not considered a means of payment but the government makes regulations regarding clear recognition even if they don't like it I think it will have a pretty positive impact on bitcoin.
take a look at some countries that have even made them a payment option like elsavador. they even proudly say that they are buying bitcoin especially now that it is priced well enough to add to the load.

I don't agree with your answer here. This might have been true if Bitcoins were around in the 70s or 80s but not today. The world is reducing its dependency on the US Dollar every year. To say that the Dollar is now the value of a independent Internet currency is not right. While dollar plays a role in the price of Bitcoins I think that we are more independent now with crypto currencies. If it was really just the US Dollar value than why wouldn't we keep holding fiat money? With cryptos we are independent of financial influence of the government and their pressure to issue new debt and print money.

Indeed, if BTC become the mainstream currency of the world all the other assets' values shall be denominated in BTC value. But Bitcoin could end up only becoming the main store-of-value asset and we'd use a more stable currency for day-to-day payments.

Being optimistic isnt bad but dont consider for this thing to happen because it wouldnt happen even on my dreams on which Dollar or fiat in general would lost its value yet we know that as long government does exist
then it wont surely happen. Why not they could both co-exist to each other? We do have some options to take whether dealing with typical centralized fiat or dealing with decentralized things like crypto.
At least we do have a choice or option to take and we shouldnt really bother ourselves or thinking off that there would be some replacement thing that would happen.
Thats not gonna happen no matter what.

I think you are asking, if BTC were the only currency in existence in the world, what would it's purchasing power be? How can that be determined? The answer to that is this: the purchasing power of a currency is the quantity or number of that currency in existence divided by an accounting of all the physical wealth that exists. So in this case:

18,923,556 BTC / [total accounting of all physical wealth such as all real estate, all physical tangible resources, all valuable physical assets that exist] = the purchasing power of BTC

In this case the total accounting of all the world's wealth adds up to $360,603 billion US dollars.

18,923,556 BTC / $360,603,000,000,000 = 5.24x10^-8 BTC, or 5.24 satoshis, per $1.00

In other words, 5.24 satoshis would represent the wealth that 1 USD used to represent. So in the United States at current housing prices, you would need roughly 1,572,000 satoshis to buy a house.

Someone check on my math.

I do not think this will happen though.

I think the question is very conceptual, because when saying value encompasses many things, for my value it is different than price, also based on the fact that it is based on the Law of Supply and Demand, things change a lot, the BTC as long as it has its support based on the supply-demand, whale effect and Fundamentals, the value can be very high, it is almost something very difficult to calculate, at least for me, I would see it as a capital gain appraisal and they are very complicated to calculate, for me the The price would be very high, to be honest the price for me should be at least $ 150k and the value would have to do the required study.

I was one of the first people to believe in bitcoin's growth, but hadn't thought about becoming a major currency yet. Honestly I'm a little afraid it will have an impact on the value of bitcoin itself. Even if that were the case, I would agree with "paying with stable coins".

Very well said. Bitcoin will never be a main currency because it is volatile and the value is still being evaluated. And primary reason why people buy bitcoin is that they will be able to sell it later for a higher fiat value.

Well, I don't think any cryptocurrency is going to be the main currency of the day in the future apart from what you just explained, we should understand that no Government can be the owner of Bitcoin and since the strength of a Nation is a factor of the strength or Value currency of her currency and this cannot be claimed in terms of Bitcoin by any Government, it is rearly that they will make Bitcoin their main currency. People and Investment can accept Bitcoin and other cryptos as it is now but that don't mean it will be the case across. 

I don't see any chances for the bitcoin to become the main currency as we still have many people in this world know don't know about it, and on the top, as the bitcoin is uncontrollable, how would you control the economy with it plus with bitcoin you won't pay taxes to the government then how will they improve the development of their country?.
Many questions may occur. For me, it's about the value. It's all about how I manage the government and the economy.

If history is any guide I don't think it will be stable nor will it become a major currency, with what we have seen so far, Bitcoin price is rising and falling steadily almost every minute, so I doubt it will stabilize.
associated with bitcoin as a whole will not be easy to predict and no one knows in the future, even though it becomes the main currency my hope seems to be taking a very long time because it is still very vague because it will continue to fluctuate.

I don't think value will be dependent upon the adoption instead valuation will be more dependent upon the play by the whales, adoption as you can see is much more than what it was an year ago but still the price of Bitcoin is somewhat less than what it was a an year ago. I think whales are going to continue their own play with the price and adoption is going to happen side by side.

adoption is only a trigger that bitcoin is recognized by several companies which will certainly make the price spike, but over time the price will go down again. Bitcoin is a cryptocurrency that has a volatile nature with high volatility, so bitcoin cannot be used as the main currency just like that. to become a major currency like Fiat must have strong price stability. Whales play a role for the volatile bitcoin market and many more that affect the bitcoin price.

@teosanru The value of every commodity or store of value always depends on the level of adoption and enthusiasm within the ecosystem but that doesn't mean the bigger fish won't manipulate the market. However, the price of Bitcoin was more than what it's was years ago because of adoption and halving effect.
@taufik123 Understand that fiat currency are also volatile in there own way. Bitcoin been highly volatility doesn't mean it cant be a major currency but it can't major currency because of it decentralization which is a setback to the government.

Really, price stability in terms of what? If bitcoin is the main currency how will you measure it's price in? Moreover in the adoption stage every currency has high price fluctuations only, many fiats too experience pretty high inflations.

Here I meant value in terms of price, what I am trying to say is we will obviously grow in longer term but valuation and pricing we will never be able to equate in terms of the adoption we are having in bitcoin.

Look, I am all for Bitcoin and the general cryptocurrency adoption but how do you think that, something with only 21mill total supply will be the world's mainstream currency? Even if many countries eventually adopt Bitcoin as a legal tender which I believe can happen, it will not replace fiat currency but will be accepted as such for payments and true value will be determined then because it should be more stable as a mainstream currency.

With the volatile price of Bitcoin, it is not possible to become the main currency, while the main currency requires a stable price. After all
the government will never allow Bitcoin as the main currency, and also from the beginning Bitcoin was not created to replace fiat. So I see
the most ideal Bitcoin should be only as an alternative to payment, it makes more sense to be realized. But there are still many countries that
reject Bitcoin as an alternative payment, especially as the main currency, really hard to come true. Bitcoin is also now more widely used
by the majority of people as an investment asset, because the price is volatile can give us profit if hold in the long term. So instead of thinking
about things that are difficult to achieve, why don't we just focus on using Bitcoin as an investment.

Foremost, bitcoin being the main currency is close to impossible because the government won't allow it to happen in the first place. The central organizations wouldn't permit the blossoming of bitcoin and before it even start to soar, they would definitely stop it instantly. But if it were to be the main currency, I bet the price of it would depend on the supply and demand because in the first place that's what really distinguishes the price position of bitcoin. The market demand and supply circulation as well as the season would predict what value it may hold.

I think Government Won't allow to happen bitcoin is main currency. So It's impossible to bitcoin main currency. Bitcoin is most popular and most valuable coin in crypto market. We already know that all coin price depends on bitcoin price. Bitcoin price now little dip i hope bitcoin price will be more increase in this year and i hope market will be green again.

It is not possible to answer this question in exact numbers, however, if you think about it, it becomes clear that it will be very expensive. That is, the price of one bitcoin will be very high - since there will be a frantic demand for bitcoin - after all, it is legal tender everywhere and everyone needs it. Such demand and the absence (suppose) of supply that could satisfy such demand - there is a shortage and prices rise. I think it's too early to talk about it, but it's always good to dream! :)

Best news? No not really because not all countries or people loves bitcoin but they only used to using the standard currency and it will be very weird for them if BTC suddenly introduced as a main currency. BTC is somewhat popular now but BTC is going to be a talk in the town once this event happen but will will this event really happen? I have a doubts on this one  because it can look very complicated.

How do we know the value of BTC if there will be no more dollar and local currencies because they will be gone too once BTC takes place as the global currency. What will the pricing of the items? And how much BTC are we going to pay to buy them.

I've often thought about this as well.

If the currency goes away and BTC is adopted as the central currency for all what would it be worth?

If BTC becomes the main currency in the world, I am sure that the world has been changing into something great. This means that the mass adoption of Bitcoin and blockchain technology have been very spreading.
Using Bitcoin as the major currency in the world is not easy, moreover, this is decentralized.
The value?
I am sure that it will be as high value, as the dollar right now.
We have seen many cases where something becomes the major, the thing will have a very high value. Moreover, if all countries similarly accept this.
But will it be?
I am not sure about this.
For we know that there is a big power of fiat as the main currency in the world. Bitcoin may be one of the currencines, but not as a main currneyc.

Once the bitcoin will be used by more than 50% of the population of the world, it will no longer be in the control of the governments to stop the usage of bitcoin or ban it. Instead the governments will themselves buy it and those who won't have bitcoin in their reserves will be left behind.
We can continue to compare the price of bitcoin with USD but after a certain time, there wil be only bitcoins and no usd or fiat currency.

That is a scenario that can obviously happen, but it is not what many think, some have in their mind that BTC can reach values of more than $200k, and it is not bad, when looking at models like the S2F it can be seen that it is not an insane amount and that it can possibly occur, however taking into account the current situation, people will not see it that way but quite the opposite, that it will not be able to arise and that it will decrease, but for me, the value of BTC could not calculate it , because it would be like doing an appraisal of capital gains, which is very difficult to do.

I am inclined to think that the fiat will not disappear no matter how much its use decreases, as discussed above. Even when gold was used as currency, it coexisted with less valuable coins of other metals. Typically this will be a process where we see more and more use of Bitcoin for payments and less and less use of fiat.

So, going to what the OP was asking, is that it is so relative. As of today we compare Bitcoin to other currencies, mainly the dollar. If in the transition I was talking about earlier it became Bitcoin unit of account, it would be the other way around, we would look at how many satoshis a dollar would be worth at that point. And in absolute terms, in the unlikely event that all other currencies disappeared and only the Bitcoin remained, 1 BTC would be one BTC but the value would be measured based on the things we could buy with it.

Well, it is a possible conclusion but it needs to take time before that will happen.
I am always certain that bitcoin would never be able to replace fiat currency, and I have no idea what its value will be until it does. It may be used for exchange or purchase, but it will never be the main currency. If you are wondering what would happen if the government allowed it, I am very sure they won't let it happen easily, and there's no way for any crypto to be worth anything given the fact that there's no assurance or measure of its value.
In short, --bitcoin and fiat should always be there forever.

For now base on what we can see and believe, bitcoin is coming up to the standard of the US dollar in the nearest future whereby it will be generally acceptable and adopted as a legal tender, though I cant say it will erase the US dollars from existence but likely to work along with US dollars as the world most recognized currency, bitcoin already is the leading cryptocurrency and the value cannot be exactly predicted as its volatile but can place a great significance other than US dollars in the nearest future.

If bitcoin is the main currency, then any government will absorb bitcoin as much as possible to be able to control it and only circulate in their own country centrally (blockchain is underfunctional). Maybe bitcoin can also be used as a reference for a country's wealth because it is a rare digital asset reserve.

Bitcoin will forever be an alternative even if it is legalized. It's not worth pairing with something that can be created infinitely.

They won't be able to do that though as they're going to need to circulate it because hoarding it won't lead them anywhere besides their economic collapse. If it's the only currency then that can only mean that the countries won't be able to keep bitcoin for themselves. I would say that bitcoin would be worth around a billion for it to be a currency used by every country because that's going to be a lot of countries.