it's actually improving safety to remove the pilots from the loop and have them perform a purely supervisory role.
Boeing designed that into the 777 with a FT-ADIRU. Even that one component was enough to nearly bring one down. It was the crew who got it back on the ground and even then they had to ignore a windshear warning which was spurious even though their training dictated a go-around.
Less manual flying, full blown erosion of flying skills - it's coming...
Not sure what you mean when you say its coming, its already here and the airlines are having to include more manual flying into the regular simulator checks. Why? Because
80's and 90's tech like those first glass cockpits (767, 757, 744, A320/30/40) with insanely unreliable and limited technology.
are still in service. The improvements in technology have had to do with fuel economy and reducing bleed air demand on the engines. The software and hardware driving the glass cockpits is still the same, just prettier to look at.