> Planes don't have to deal with semi-trailers or wildlife appearing suddenly in their path regularly either
Planes most certainly do have to deal with wildlife (e.g. birds) appearing suddenly in their path regularly.
This is a ridiculous statement. Are you seriously saying that birds regularly fly at over 30000 ft? Or are you trying to imply that autopilot during landing/takeoff actively tracks birds and tries to avoid them?
In other words, the plane autopilot doesn't "deal" with wildlife at all unless you count running into it. Which is apparently what Tesla autopilot does as well.
Autopilot in a plane doesn't have to deal with obstacles besides the odd mountain here and there.
So I'd say that in many (most?) ways it's easier and safer to autopilot a plane than a car, and as you say, even planes with autopilot have failed.