Could you see a future wherein the entire world shares one global currency, be it fiat or crypto? If I think it in a scifi kind of way, it would most probably be some digital currency that could all just use. It doesn't even have to be in this century. Maybe the next?
This could be difficult to control when we have different culture and economy every country as the standard is not the same. Policies every country had different and this can bring chaos and misunderstanding in every people. Maybe this could be possible if we have only one leader to decide for the whole world.
of course it will cause chaos, I can't imagine if the world only has 1 currency, how to distribute to many countries, how the economy is described in a country (because there is no local currency), and who will control the circulation of this currency (if only one currency)..
A chaos that will not even be able to resolve. Every country worldwide, unless there is a country that is not independent anyway, sure do have a say for their own country, and for something like a global currency to even be a thing, there must have been a country that would want to impose it on other countries and I wonder how that is going to work out.
Just as we have had in the past with USD being a globally accepted currency and every other country still having their own local currency, I would say it is the only thing we are going to get to see which would be an alternative that is accepted worldwide and nothing else.