Do you think it's possible Bitcoin will become a "global unit of account" in the future? If not, why? What would a world without Fiat really look like?
I get what you’re trying, but I can’t really imagine the world with just one asset being used. Bitcoin has a fixed supply and it might get to a point where that might become another problem for people around the world, unless maybe when it gets to that time they will look for a way to fix it, maybe by increasing the amount of supply? This topic has been discussed several times in this forum.
I am of the opinion that all can stay, and people should be completely free to choose for themselves at every moment what they want to make use of. And same way, stores can decide whether to display their product prices in BTC or in USD, or whatever currency.