>>74727
The only thing backing fiat at this point is that they're in use. The government doesn't know how much to print, so prints too much, and can't bring it back in with interest rates or taxation since those don't apply on savings unless they want to enforce it at gunpoint like during the period from the 30s to the 60s, eventually crippling market efficiency with national cartels, or be overthrown.
The cryptos hold no value but they destroy excess fiat. If someone is stupid enough to borrow money to buy crypto, which doesn't have value, they're an imbecile and their money deserves to be destroyed. The higher the value of crypto is the higher the amount of excess cash in circulation. Since it's excess cash that's produced no value it's equivalent to the zero value of crypto anyway.
Until crypto becomes institutionalized as a unit of exchange the risk of a zero crash exists, when simply no one will buy it. However, fiat is continuously inflating forever, there isn't enough precious metals, and thus it will be bought. And once someone accepts it as something of value, like the debt sticks in Medieval England, it becomes something of value.