The problem is, in order for Bitcoin to become a currency everyone will use, it should be stable. I know that you might say that people will still use it because it's not about stability, it's about freedom and technology. I agree with that, but Bitcoin needs to be stable in order for people to treat it like money, and not like an asset.
I am not sure that the main reason why bitcoin is not yet used as a currency for everyone is its instability. Fiat currencies are not stable either, otherwise we didn't`t have such phenomenons as inflation, deflation or devaluation. I have a lot of doubts if it is even possible to create a stable currency, not speaking about its usefulness and effectiveness.
I believe, that bitcoin has bigger problems to become a currency everyone will use due to lack of necessary (yet) identification, which cannot be avoided when working with fiat money. Which country or government will be satisfied with that? The inability to limit, block or take away the account in which your money is stored makes you free and independent. And that is definitely not the goal of the world order in its modern form.
some fiat is unstable because its value depends on the economy of that country but it is also not as volatile as bitcoin, which can lose 50% or 80% in just a few months. Bitcoin's volatility is not the main reason it can't be a currency, but it is also part of why no one wants to use such a highly volatile currency. when you bought bitcoin for 50k, it is now trading at 26k. Do you dare to spend your bitcoin like fiat? surely you won't either.
Bitcoin can become a currency or not is decided by the government, and bitcoin is decentralized so even if it is stable, I don't think it will become a currency. no government can accept a currency that is not controlled by them.