This is one problem gold bugs seem to gloss over: sure your currency might technically be backed by gold (or whatever) but that's only the case because there's an enforcement mechanism on the humans involved (ie the government). And that government only exists because the people collectively will it. So there's really no difference between this and a fiat currency.
It gets even funnier when Crypto Bros start proselytizing about blockchains. Here one tiny part of the system has been replaced a simple consensus by computers. But that's where it ends. As soon as crypto (including NFTs) meets the real world, meaning if you use your Bitcoin (for example) to purchase something (weird concept I know) that isn't on the blockchain as well then you've just added a trust requirement where collective delusion has to act as an enforcement mechanism.