> ... building codes...

I agree that in an ideal world that would be sufficient. But in practice, governments rarely deploy trained actuarial to make decisions, rather relying on politics and shoddy studies. Government codes also change very slowly. Insurance companies (whether private or public), under the financial incentive, are constantly changing their policies and rates in response to new data and calculations. I would be open to looking at studies that resolve this question one way or another.

> ... car seats...

I grew up in a poor global south country. Rich people, who clearly can afford them, don't buy car seats. Many people who live in countries where they are forced to buy car seats, when they come back on vacation don't use car seats for their kids. People can be very irrational.

I'd love to see this argument used to get rid of legal authority to create building codes. You make a great point, and you're effectively pointing to the fact that, at least for that specific problem, the market is much more efficient and solving the problem than government regulations.

The car seats one is tough. If you've seen first hand examples of people actively choosing to forgo car seats, I'm not sure if that's a problem governments should solve. Unless the state directly claims "ownership" as it were in the child, the parent is their legal guardian and if the parent makes a terrible choice they have to live with the repercussions. We don't regulate all decisions that can harm a child, that's a tough line to draw.