Currently, there are many usd-based stablecoins such as, usdt, busd, usdc and maybe many others. To be honest, I used to think that crypto would completely eliminate the usd's dominance of the world economy but I was wrong, it turns out that usd is now evolving to crypto (stablecoins). What do you think, whether in the future bitcoin or other crypto can replace the role of currency in each country and leave fiat currencies such as usd, euro, yuan and others.
It is better you do not get your hopes too high about this happening in the future, while many of those that came early to the market and adopted bitcoin have had a similar dream the truth is that was not a goal of satoshi, satoshi created bitcoin in order to help you to truly own your money and become your own bank by not relying on a third party to approve your payment, satoshi succeed since you can already do that and the dead of fiat currencies is not really needed.