Have always wonder which currency would the world accept if only one currency was to be used. Maybe the dollar?, don't think so, The British won't tolerate that.
Cryptocurrency?. Maybe. Until the advent of cryptocurrency, I never thought that would be possible but it seems possible.
The world is not too far from a unified currency.
It is already the Dollar and yes the British do tolerate it. Everybody price their assets in dollars. Everybody. It doesn't matter what you buy. Bitcoin, stocks, food, land, gold, beer... all of them have a dollar price tag. So the answer is pretty clear. Crypto won't be the thing because it is way too volatile. You don't want to pay a different rate every day for a can of beer.