The problem is that gold and crypto are priced in relation to fiat and if fiat ceased to exist, you wouldn't be able to price either. When splitting gold or crypto among fellow citizens (yes, these assets will become shared between everyone), you wouldn't be able to do so without some form of IOU, which effectively would become another form of fiat. It's a catch-22 situation: while fiat exists, gold-bugs and crypto-bros feel smug, when there's no fiat, everyone is suddenly unhappy.