Considering how Americans view other Americans (I hear "stupid" thrown around a lot), I strongly doubt that a decentralized authority would ever gain enough trust in the US to take hold today without a strong historical precedent.
For what it's worth, cash is still centralized. It's made "legitimate" by the power of the central government, and is managed & controlled by that authority. Given, it is somewhat "decentralized" because the value of fiat money comes from the people's agreement that the currency has value. On the other hand, the US dollar's global hegemony exists in large part because of global US Military presence, which is absolutely a "central authority".