I don't think that's necessarily as good as it gets. You can have commodity backed currencies. These are much more stable but much more difficult to manipulate which is a power many governments want.

One is not necessarily better then the other. You can't force growth in a commodity backed currency by incentivising certain usages by messing with inflation.

Which is ultimately backed by the American people's toleration of the government that holds those powers. Its a layer of abstraction that bitcoin lacks, which makes USD much more less volatile than bitcoin (along with a bunch of other things).