That is literally nothing. It’s worth what they say it is worth.
Bitcoin and monero is worth the efforts of the community to support it. Pretty much nothing backs FIAT, that is LITERALLY what fiat is, fiat is Latin for “let it be done”.
You can argue that without FIAT currency, crypto has no value, but in reality that is not the case because they have their own value. That value is determined by the community as well as the difficulty and abundance of coins. It is literally more stable than real world cash, you just have to USE it as such. ACTUAL COINS, not shitcoins.