Would Bitcoin no longer be Bitcoin if it were adopted by everyone in the world ?

[Minor Miner]

If Bitcoin was to become a globally accepted cryptocurrency I think nothing else matters, the price of Bitcoin isn't the reasons why we should be using Bitcoin instead we should be using it because of its decentralized nature. We can always have other investment opportunities we can capitalized on beside trading the up and down of Bitcoin price.

What you say is Satoshi's original purpose in creating bitcoin, but things are going in a different way. Bitcoin has become a form of investment, and everyone is entering this market just for profit, including you and me. Most of us are here for profit, not for the decentralization it brings. If bitcoin becomes stable one day, I believe many people will leave it and find something that can be profitable for them. But either way, OP's hypothesis will never happen, so expecting bitcoin to become stable will never happen.

[rokok lokal]

Assume one day, Bitcoin would be the only survivor as cryptocurrency in the world and each individual, company, organization and goverment would abandon all fiats/currencies and take Bitcoin as the only payment. When all obstacles were gone, Bitcoin would actually become a combination of both fiat and investment asset. However, as demand and supply were not to fluctuate much, the price of Bitcoin would be really stable and the value of investment would deteriorate. The two factors/purposes (fiat vs investment asset) will be contradicting each other all the time. If that happened, what's the point of making Bitcoin worldwide acceptable while losing its value and nature of Bitcoin ?  Metaphorically speaking, the hunting dog may be killed when all prey animals are gone.

What is your opinion ? Please let me know. Thanks.

Very interesting, but I'm thinking what will happen if finally BTC and Gold will be mass adopted as a legal currency used in the future.

[Antonas1]

As long as every country in the world has a government, Bitcoin will only be a payment alternative. If fiat should be destroyed, the government will definitely create another centralized payment system.

2.How the millions of people, who don't have access to electricity and internet are going to use Bitcoin? Will paper Bitcoins become a thing?

If electricity is the biggest problem, why did the government create a CBDC? Isn't the same?