These costs still exist in a hypothetical year with zero fires, though. Additionally, people whose house were just on fire with zero insurance are probably not in a good financial position (anymore), and they are unlikely to be able to pay…

If you don't have the money, then a lien is placed on the property and it will be sold to pay the debt. Or you can take out a mortgage to buy it. In any case you'll be richer than if the house is burned down.

Ability to pay still not guaranteed, depending on the financial situation. Family can easily have more that's than assets to their name, preventing collection.

You can prioritize firefighter debt over other liens.

And it doesn't have to be guaranteed if it works 90% of the time.

Your first problem is trivial cuz you can look at a multi-year average.

The second part is more significant in people simply don't have the money to pay.