It would be awesome if the US decides to do that, but I don't think it's very realistic right now. The volatility in the bitcoin market is still too high for it to be a good store of value for everybody. Historically the Gold price has kept it's value for a long period of time, we haven't seen a price drop of 50% in a few months before with it. That is why it's so attractive for the older generation as an investment to store value.
The USA will not do that for sure. They are the most liberal nation in the world so they should technically speaking be the one to do it, but they care about their USD a lot. And right now they are doing fine, even though domination of USD goes down, the value of it goes up, which means that there will be a reversal soon and people will start using that all over again.
I just do not see how it is even possible, think about how big the USA market is, and if it happened that would be awesome. But right now, even Coinbase is down like 80% in the stock market, it's just not a nation that is seeing crypto as the get out of jail free card situation, they won't do it.