Responding to your edit:

Perhaps in a theoretical sense they aren’t different, they are fiat money which is basically a ledger of value (which governments manipulate).

But behind the dollar is the largest economy in the world and the largest army by a long shot, and a lot of motivation to keep the dollar as the “biggest” currency in the world.

It could be worse, it could be better. All that it matters with currencies is trust. Trust that they can be exchanged and trust that they keep their value. If I go shopping tomorrow and they tell me, you can keep your euros and your dollars, we want only bricks because currencies are crashing and bricks will be useful forever, I better have to get out and find some brick. The dollar is fine until people will trust it.

> How is USD better than Zimbabwean dollars

It’s backed by the most powerful nation in the world.

The Zimbabwean dollar had MONTHLY inflation rates reaching 79,000,000,000%.

Fun story: There was an advertising campaign for a Zimbabwean newspaper with posters and handouts printed entirely on Zimbabwean dollar bank notes https://en.m.wikipedia.org/wiki/The_Trillion_Dollar_Campaign

Nobody wants to get paid in Zimbabwean dollar.

> after the US federal reserve has quadrupled the amount of dollars in less than a year and then claimed only single digit inflation

Inflation is a measure of how much things cost, not of how much money exists.

If quadrupling a country's money does not cause runaway inflation, then there is something deeply wrong going on

Your failure to understand something doesn't make it wrong

Your reply contributes nothing at all

It's not like he can understand it for you.

Replying to edit: technically there’s no difference and this technicality doesn’t matter one bit. You’re being told the answer and fail to see it.