Sure, if you just fixed people, that would work better than any conceivable technical solution.
But you can't fix people, so there's no point in complaining that *some* people are *sometimes* stupid, careless, or irresponsible..That will never change. Sometimes, even, that careless person might be *you* on a bad day. We all rate ourselves based on our performance on our good days; which is why we all think we're better-than-average drivers, but really our risk to ourselves and others is dominated by the days we didn't get enough sleep, are stressed out, distracted, and running late. Those are the days when the things we habitually do right go out the window.
If you frame the root of the problem as being "people aren't good enough to operate the world we've built", then you're stuck putting band-aids on the problem. That's not unreasonable as it sounds, think of how things would be if you didn't *have* band-aids. People would be getting limbs amputated because otherwise insignificant cuts got infected.
So it's perhaps better to frame the problem this way: the world we've built is not suitable for people to operate in with acceptable safety. The root of the problem is design, so that should be highest priority. But even so, we'll still need to address the failures that better road design can't fix. Even the most safely run factory still needs a first aid kit, and that first aid kit is going to be stocked with band-aids.