Noted. I'll attempt to put more nuance in my one-sentence comment next time.

Modern fiat currency is backed only by debt. The fact that money can be backed by debt implies that there agents have a sufficiently sophisticated ability to judge trust of other agents. It's not extremely relevant that trustworthy behavior is enforced by the state.

This is also not true.

GDP, long term economic prospects (of which debt is a part), and political stability are all major factors in fiat currency value.

This is not as bad as the original oversimplification but it’s a pretry incorrect one by itself.

What about the power to tax? All governments operate within the fiat currency framework.