It's not true because of "eventually" it's true because of "fiat". When an entity (e.g, the government) decrees (which, remember, is what the word "fiat" means

It's not true because of "eventually" it's true because of "fiat". When an entity (e.g, the government) decrees (which, remember, is what the word "fiat" means) that some piece of paper or entry in a database is "money" is when the trouble starts. I prefer my money to be a medium of exchange and account as well as a store of value that I can trust which, by implication, means it cannot be decreed to be so by some "authority".