Gold value was also enforced by armies and taxes. It has uses nowadays that it did not use to have. Used to be gold was only useful as a decoration or as a coating that wouldn’t tarnish. The actual value was that you had to pay taxes in it.

Crypto has no value, less value than fiat even, because I can’t buy groceries with it, nor can I pay taxes with it.

Also, you can’t fractional reserve crypto unless you’re using a second crypto currency backed by a first.