This is the closest thing to correct, more specifically USD is backed by some real-estate and mostly TBill which is the government's ability to pay it's debt.
There's some sketchiness there, but generally it works, and of course, there are externalities like petrodollar but generally it's a sound currency.
It's not a super store of value, but it's not meant to be, there are other assets for that.
BTC is about as financially relevant as a GameStop mob, so if we're going to understand it, its' for the populist psychology, not for anything else.
