Plane crashes are rare because when they do happen they're so horrible. Dozens or hundreds of people may die, and millions of dollars in damage could result. So to minimize plane crashes, we've set up a whole system of safely building and flying planes with tons of regulations and years of training for the few people that we let fly planes at all.

In a car crash, only a few people might die, and often just the driver...so we let pretty much everyone drive a car with minimal training. Therefore, quite predictably, there are more car crashes than plane crashes.

But if we wanted to, we could make car crashes just as rare as plane crashes! Getting a drivers license would be limited to a few thousand people, require thousands of hours of training to get, require frequent re-certification, and there'd be nearly no tolerance on having a license ever again after making even a small accident. We do all of the above for pilots, precisely because plane crashes are horrific when they do happen. But for cars that much control is unnecessary vs the smaller risk presented by car crashes.

So, at least for your example and other human-related things, it's kind of self-balancing: The worse a potential outcome is, the more time and money it's worth spending to make that event as rare as possible.