That is not a fact at all. Fiat money is currency made up by a government, not backed by anything of value. Gold is not nor has ever been fiat.
Sorry but gold, like every other currency, only has value because people are willing to take it in trade. Things of true intrinsic value would be useful when lost: food, shelter, tools. IE stuff we used to barter. Money exists to be an exchange layer on barter, so you don’t have to carry your chickens all over town. Anything useful, intrinsically valuable, innately makes bad money because you wind up using it for other stuff. Gold is the original fiat currency. But it was currency so long a lot of people have forgotten that it’s value is totally added by people.