Almost anyone in the world is (currently) willing to accept a US dollar. There will be some exchange rate and transaction fee, so maybe I demand three dollars instead of two.

This is exactly the same with crypto. You might argue there are technological barriers to using bitcoin but many of those barriers apply to petrol-dollars as well.

The whole premise of bitcoin is that the line will continue going up

The whole premise of fiat currency is that the line will go down so rich people constantly need a ROI and poor people are constantly pushed deeper into poverty. This is not a superior system.