Yes, sometimes, some other vehicle will swerve and force you off the road. That seems to be the exception, not the common case.
Very rarely, a mechanical fault will cause an accident. But, even those are generally do to lack of maintenance. Personal example - I was almost hit by a detached car wheel/tire a few months ago while riding my bicycle on a bike trail. The car was an old beater. No muffler, rusty, etc.
Current laws don't do much, but an incident like that should be a minimum automatic five year suspension with mandatory re-testing.
Click on the last link and watch the video. It's a video that can only be described as a brutal and unprovoked attack with a deadly weapon, caught on camera. The author described it as "attempted murder." If someone was caught on camera beating someone else with any other weapon (nightstick, bat, hammer) police would be a lot more interested in following up and making sure the attacker doesn't attack again.
I think the big problem is there is rarely any sort of investigation unless it's really, really egregious. You just say "whoops" and maybe get a ticket for speeding or failure to keep right or running a stop sign and that's the end of it.
The fact this comment actually exists shows the problem.