And in reality, the operation of an aircraft is not the principle point of failure. Rather, mechanical failures, weather, sabotage, etc. are much more easily eliminated by rigorous inspection and heuristics with multiple failure points.

The fact that commercial pilots (with numerous hours of experience, strict certification and simulator requirements and often, military backgrounds) are considered a principle risk point is only because the safety standards of all the other modes of failure have been so robustly reduced.

Exactly. If pilots (humans) cause errors, the safest system removes them from the equation as much as possible, except in the parts of the process where it would be more error-prone not to.

Point re: screwing up because the plane is normally flown for you; yes, but that's still safer overall without a doubt than optimizing for pilots doing much of the flying manually much of the time. Occasional emergencies are far better than predictable human error all the time.