In the old days, flight crews used to consist of a radio operator, navigator, flight engineer, first officer and a captain.
All but the first officer and the captain have over time been made redundant by technological progress. Which is good for the airline because fewer personnel is better for the profit margin. It is also good for Joe User because lower crew costs allow airlines to compete more on ticket prices.
When the flight engineer was made redundant in the late 80's (taking my future career with it) there was a lot of discussion about the potential impact on flight safety. A pair of eyes and hands less on the flightdeck was going to impact flight safety in a negative way, some thought. I don't know if there are any comparative studies on the matter but flight safety (fatalities per revenue miles) has only improved over time.
When I left school the joke was that eventually there would be only one pilot on the flight deck, with a red button that says 'LAND', and a dog.
The dog was there to prevent the pilot from pressing the button inadvertently.
So it looks like we've almost arrived at that point. With the airplane taking off and landing itself the captain has his/her hands free for the comms and activating the missed approach procedure. There is no need for a second pair of hands on the flight deck to lower the gear or set flaps and I imagine (with the technology already available in cars) it would be trivial to monitor the pilot's face and eyes for signs of fatigue and loss of concentration.