Earlier quoted context omitted.
Fiat currency, in essence, is equally valueless. It only has inherent value because enough people agree that it does. Bitcoin is no different (and in fact has several advantages over fiat, giving it further value).
Well, not quite. It has inherent value since fiat is guaranteed to be backed by the full faith and credit of the backing nation. That is, by holding fiat, you trust that the country issuing that fiat doesn't default (and will hence guarantee that value). I don't see a similar parallel with crypto, though I'd love to be corrected.
Neither is it backed by the US military or the ability to pay taxes.
The fact that the dollar is in widespread use in a country that has a track record of stability, a well-managed economy, trusted institutions and a strong military all mean that if you want to put your faith into an arbitrary and made up asset, the US dollar is an excellent choice; but its value is a collective illusion nontheless.