@stan,
Who backed Fiat? For me no one! Banks (Central bank of the country) make them in the thin air. There are no ledger how much of Fiat printed and how much of fiat in the market place.
But in crypto world, everything is in a ledger. So if someone says crypto is not backed by anything, I would like to say, whole world backed it, only banks hate to do that :D Coz they fear to hear the truth!

Cheers~