This kind of approach never works except for in the most egregious of situations. Just imagine what the state of car safety would be like if it was purely left up to the market. Regulations work.
https://www.euroncap.com/en/car-safety/the-ratings-explained...
Steep financial liability for pedestrian/cyclist accidents for not only the driver but also the vehicle manufacturer or anyone involved in modifying a vehicle would also help.
The question how valuable consumers perceive safety features to be, and what their rate of adoption would be; additionally, which ones would they choose? Two interesting examples are seat-belts and air-bags; the former is in the thousands or tens of thousands of dollars per life saved, and the latter is generally estimated to be in the millions of dollars per life saved. Was mandating the air-bag the optimal way to use that money, or did the government commit statistical murder (a term often used in the field).
And it's compounded with things like housing and food. You can't go without either unless you want to live a completely undignified existence and with a vastly shortened lifespan.
Another example to throw in there is indoor smoking too. People never stopped going out to eat or to bars when you were forced to sit in a thick haze of second hand smoke, and even if you did avoid it there were hundreds of other people who didn't care. I can't imagine how things would be if the push to get rid of it happened in more recent times rather than 20-25 years ago. Red states certainly would have never banned it and there would be droves of people going out intentionally to force you to inhale their second hand smoke to own the libs.
I think even diehard libertarians would admit that "regulations work" in the sense that using the government's monopoly on violence to force companies to do something will cause them to do said thing. The debate is whether the upsides outweigh the downsides (eg. due to regulatory capture).
For a point of comparison, software security is largely unregulated. There's no law that says Google needs to deliver security patches for 5 years, or they need to implement security measures like verified boot, yet they do so anyways, presumably to compete with Apple which is doing something similar.
That isn't really the debate, because we had that debate and decided it was (see seatbelts for an example). Though I guess literally every issue could technically be relitigated and debated constantly ad infinitum, so you're not technically wrong. But we didn't listen to people who said "if you want seatbelts required, just stop buying cars that don't have them".
What we see now, for the most part, are individuals who disagree with our consensus, but that's to be expected no matter what we had ultimately decided. So in this case, "it worked" is shorthand for "it successfully got us closer to achieving the goals we decided on"