The most popular fiat currency, the US dollar, was tied to gold until 1971. It's still not clear that breaking that link was a good move.

Also this: https://wtfhappenedin1971.com/

It's prone to boom and bust which has been devastating. Hayek describes a type of money that adjusts it's supply to maintain a stable price. Until now this wasn't technically possible. Ampleforth.org is an interesting experiment to introduce a new base reserve with dynamic supply and eventually a stable price. https://m.youtube.com/watch?v=9-uo-KfnkhI

Economies boom and bust. This has nothing to do with fiat currency, and is a heck of lot better then the alternative where shopkeepers and employees are made poorer due to economic prosperity because they don't adjust their prices fast enough.

or it's non-vc fork - https://based.money/!