The evidence that car seats save lives is significantly weaker that you probably believe, as I detailed in another comment in this thread. But look: even if car seats make sense for a typical 5 year old on a typical drive in their typical car (which is a higher evidentiary burden than you might think), a mandate imposes a huge logistical tax that makes many normal things completely infeasible or impractical:

- travel with many kids (nope, physically can't carry 4 car seats plus luggage)

- using a taxi, e.g. to go see a movie (nope, can't carry a car seat into the theater)

- carpooling with other families (I'll drive them, you pick up? Nope, we'd have to shuffle car seats around.)

- rides with grandparents or other family members (sorry, we'd have to deliver the car seat to them first)

- splitting kids between two vehicles for errands (let's spend 10m wrestling car seats from one car to the other first)

The whole texture of independent childhood is altered by car seat mandates! Everything gets filtered through "is there a car seat available?". If you haven't experienced this, it's hard to describe - and I think it's absolutely a case where tradeoffs like "how will this affect quality of life?" are completely overridden because "well, if it just saves one life..."

But sure everything would be better if any moron was allowed to decide how to keep their own kids safe.

Yes, I think that we'd all be better off if every person was allowed to have their own personal values, deciding what's more important to themSELVES, rather than piling on and trying to force every one into a one-size-fits-all solution.

For my part, I'd much rather have people wishing me "have a rich and fulfilling life" rather than "be timid and careful to maximize your time even if it's boring and unrewarding".

Sure, you can disagree with my priorities, but that's the whole point. We should each be able to have our own priorities.

The evidence on car seats is extremely weak and they prevent only a handful of injuries. You'd be better off redesigning roads or having more collision protection systems in cars. As self-driving cars get better to the point where they can communicate and eliminate many human errors, there's probably no need for car seats at all. In many situations they make things more dangerous, not less.

>allowed to decide how to keep their own kids safe.

This was not the major factor, but when things were still like that, it was not only NASA that made more forward progress than later times.