I cannot believe this is getting downvoted. The reasons cars are inherently dangerous is 99% because they are heavy and fast. Everything we build around that (traffic rules, dedicated lanes, buffer spaces, ...) is purely to deal with this fundamental physical reality.

With great power comes great responsibility. Whether you take that perspective in Joules, Watts, Newtons, kg.m/s, the conclusions are roughly the same. Drivers needs to be hundreds of times more responsible than cyclists or walkers.