Fiat money, aka currency which isn't backed by gold, or any other commodity (like the dollar for instance), is indeed stupid and quite literally a scam.... I'm sure this isn't news to you though, nor is it worth pointing out which particular tribe has excelled in this field and profited handsomely from it.
Whether or not a currency is fiat only matters to how that currency is valuated, distributed, and traded.
It would still be a stupid thing/concept upon which to base a civilization.
Wealth, it's acquisition and disbursement, is not a governing principle.
It's a tool for facilitating trades; money for labor, money for goods, money for services, etc.
Those trades could be anything we want.
Money is just one of the options.
Money is not suitable as a political guiding star; governments should serve people... not capital.