In fact, it's still too early to talk about a complete replacement of convention

[DinGaz]

1. Crypto currency has not yet become widespread. Yes, digital cash is spoken at every corner, but in fact this circumstance means nothing. Virtual money is at the initial stage of its development and their integration into the international financial system is just beginning.

2. In most countries, digital money is outside the legal field. Perhaps, this is the most painful problem of crypto currency. Not all countries are in a hurry to legalize virtual assets. There are also states that have completely banned the crypto currency and everything associated with it.

3. Lack of trust on the part of ordinary people. Most ordinary citizens consider virtual cash an ordinary pacifier or a cunning financial pyramid. People are not used to trusting what they can not support in their hands. Adding oil to the fire is also fraudulent ICO-projects, which leave investors with empty pockets. Do not forget about the hacking of large crypto-exchange exchanges, as well as cryptotices. The society does not fully understand the specifics of virtual money, and this ignorance causes fear in them. How do you think, will people refuse in such conditions from traditional money? The answer is obvious.

4. High volatility of the crypto-currency market. The cost of individual coins can vary with the speed of light, so the digital cash market is considered an ideal platform for financial speculation. Can a volatile speculative instrument become a full-fledged monetary instrument? No and no again! It's just impossible. Crypto currency will not replace ordinary money until it overcomes its insane volatility.

5. Lack of a developed infrastructure that would be sharpened to work with digital money. You can not buy bread for Bitcoins or leave a tip in the form of a crypto currency for the waiter. For this purpose, there are no suitable technical means yet. Any traditional money must comply with the principles of free exchange. Simply put, you should easily spend it. Crypto currency can not offer such opportunities. Yes, now you can already buy cars and houses for Bitcoins, but it's a drop in the ocean. Try to buy with the help of a crypto currency, for example, tickets for a bus and you will understand what is at stake.

Is everything so bad?

Of course not. Of course, the crypto currency can not completely replace traditional (fiat) money right now, but that does not mean that it can not replace them in principle. Technological progress shows incredible growth rates, so no one can predict with absolute certainty what will happen in a few years. Look at Japan. Crypto currency is supported there at the state level. For example, in Tokyo, you can easily exchange your cash for virtual money in special exchange offices and spend it in the nearest store. This is the future that is happening right before our very eyes and very soon it can become our daily routine.

[alesnoy]

Not bad reasoning. I agree with you and help you

[adzino]

2. In most countries, digital money is outside the legal field. Perhaps, this is the most painful problem of crypto currency. Not all countries are in a hurry to legalize virtual assets. There are also states that have completely banned the crypto currency and everything associated with it.

Don't mix up digital currencies with crypto currencies. Though crypto currencies are a form of digital currency but they are not the same. Normal digital currencies are actually legal almost everywhere. This is because digital currencies are actually centralized and controlled by a group of people who regulates them following state laws. Almost all digital currency (e-wallets and other stuffs) has a legal framework which crypto currencies lack.

[suzanne5223]

2. In most countries, digital money is outside the legal field. Perhaps, this is the most painful problem of crypto currency. Not all countries are in a hurry to legalize virtual assets. There are also states that have completely banned the crypto currency and everything associated with it.

Don't mix up digital currencies with crypto currencies. Though crypto currencies are a form of digital currency but they are not the same. Normal digital currencies are actually legal almost everywhere. This is because digital currencies are actually centralized and controlled by a group of people who regulates them following state laws. Almost all digital currency (e-wallets and other stuffs) has a legal framework which crypto currencies lack.

Firstly,  e-wallet are eletronic wallet, digital wallet or online paymeng not digital mone and there is nothing wrong if the OP  cryptocurrency digital currency since it a virtual money. However, some crypto currency are also centralized (NEO, EOS,XRP etc).
With that been said. The reason why cryptocurrency are yet to been legalize everywhere is because most government lack the concept in it because they believed it will end Feds