> You can wrench attack them, but that’s the only option.

That's not the only option for a government. You don't need those specific coins, you only need anything of value. Their car, their house, the wages their employer would have paid them, anything else they'd already bought with the money, etc. And they're criminals, they're going to jail, and they're staying there a lot longer if they don't give back the money, which has a way of making non-compliant people more compliant without hitting them with a wrench.

> The only way it’s possible for there to be recourse even if the scammer is noncompliant, is for there to be a fiat money system.

That doesn't give you recourse either because they can spend the money right away. Which transaction are you going to reverse if they use it to buy a physical commodity or foreign asset? Then the scammer has the asset, not the money, so the only thing a fiat money system can do is cause the victim to be the innocent asset seller instead of the potentially negligent or actually in on it person claiming to be the original victim.