Why not have a balance? Automatics in, frees up capacity in busy airspace. If one pilot flying, one doing everything else, then who is monitoring? When its quiet and nice weather, great, brief the other pilot, disconnect everything and fly the thing manually all the way in. If it's quiet and the weather not so nice, the same can apply, provided, if it starts getting too busy/ not so comfortable you are happy to put the automatics back in.
That way, manual flight is practiced in the safest environment, so skills are not lost, yet when its busy you have both pilots monitoring by using the automatics as a 3rd pilot.
Best of both worlds, and surely we are paid for our decision making as much as our flying skills?