Part of why this is a problem is because car companies compete with each other on safety. And a good way to do that is to add more mass to your vehicle so that in a car crash your own maintains more momentum and therefore imparts less of a deceleration on you than a smaller car would. So the end result is a arms race between car companies to build bigger and bigger vehicles (and also less fuel efficient ignoring ICE improvements in recent years).

Compare that to airplanes where instead of competing for safety, they all cooperate on safety. The end result being that all planes are safe and rarely crash. Granted, airplanes are inherently at lower risk than cars due to their being less of them and them being separated by large distances in the sky. But in the end cooperation vs competition of safety makes a big difference in everyone’s safety as a whole.