All one has to do is remember Air France flight 447 to see the potential problems. In that case a poorly trained pilot was the problem, and of course with instrument failure, automation also failed. Today the milataries have drones controlled from far away, and such capabilities would be an additional safety feature, should all pilots become incapacitated. That would also allow naferious activity from outside the aircraft. One pilot, two pilots, three pilots, zero pilots, it really doesn’t matter, if all possible situations can be handled. In spite of pilot errors, I’d prefer at least one capable pilot on hand for unexpected occurances. There will be such.