No government can create money by fiat, neither can any government set a value for their own currency. Fiat currency should always be backed by something, either by hard assets directly or by other fiat monies that in turn backed by those hard assets. Even if a government says that its currency is backed by "the full faith and trust in the government that issued it", it lies. No one trusts money that has no strong support in the form of hard assets. Bitcoin, on the other hand, is a hard asset itself, which means it is not necessary for it to have additional hard assets that would be backing it up. Bitcoin doesn't have value because someone said so, but because its value is observable for everybody who wishes to see it. It has certain strong characteristics and unstoppable decentralized nature that make its superiority unquestionable, especially against fiat monies whose value depends solely on hard assets like bitcoin.