Why would you choose a financial instrument that's only a few years old to replace the US Dollar? There are some primary use cases that crypto solves in regard

Why would you choose a financial instrument that's only a few years old to replace the US Dollar? There are some primary use cases that crypto solves in regards to international monetary transactions, but there are big questions in terms of technological maturity, and most especially around governance. I love crypto, I think its potentially transformational. But it just isn't a contender yet. It needs to scale and it needs to mature.