This is impossible to happened since each country preferred their own currency which the can print money out of thin air. Bitcoin has limited supply and decentralized, there’s no way that the whole world will unite just to use Bitcoin as world currency while they are competing to each other to make their own fiat have more demand on international trade.

I believe hyper inflation is one of the occurrences that will make the price of Bitcoin high in terms of fiat value since fiat buying power will decrease that will reflect on Bitcoin value opposite.

Anything bad news related to fist will make Bitcoin more appreciated.