I lived in Ukraine during a period of like 1000% inflation period month. At the time USD was the value store or choice. You get paid on the 1st of the month and if you don’t turn that cash into USD, by the end of the month it became almost worthless. Nobody could pay with USD (except the bribes), but you wanted to minimize the time you held Ukrainian currency as much as possible, down to hours if you could.

I mean, the US does... every time the question of whether US bonds are worth it, the answer is always "sure, it's backed by the US government"

Bonds are not dollars. Bonds have a positive return. Dollars, by design, have a negative return.

My bank offers savings accounts.