Kind of, yes. The usd is considered the world's top reserve currency and there are many cases similar to what you described above. There are literally billions of dollars that exist overseas and never even transact on American soil. However the pound was the reserve currency before this and I believe it was the Dutch east India company (Netherlands) that was the first to be a reserve global organization. there's nothing permanent about the usd that cements its status as the reserve currency forever. If we're asking why is the dollar worth anything at all it has to do with the assets of the USA (military, land) and nebulous cultural icons like LeBron James, Michael Jackson and Beyonce. It's tough to define but the essential question is one of trust. The US is flawed but the flaws are on display. Someplace like China, the books are cooked by a central organization and can't be trusted