Full automation will work perfectly...................
We'll just have to wait a few years while they work out the weather control, eliminate any failures on aircraft, and anything else that can affect a flight.
Of course it will help to if the fully automated autonomous systems can programme themselves.
Otherwise we are still back to the system only being able to respond in the way a human has programmed it to, if that human omits one set of circumstances, the system won't respond in the way intended.
No computer can yet come near the human brain, and even allowing for the ever accelerating advances, it won't happen for many years.
The experiments with "pilotless" aircraft at the moment are not really very advanced, they will work when conditions are within the parameters of the programme.