Sure, thing is these issues are extremely rare (and not just over populated areas) And that is why you still have pilots, and redundant systems, so yes as a system an aircraft is a lot more complex. The traffic environment is not, the high level of control of air traffic and its standardization is making sure of that. And the latter is making i easier for aircraft because they have to deal with a lot less randomness.

So, I could imagine developers of self-driving cars could learn a thing or two from aerospace. But that is just my opinion.