And Altas - as for formation flying skills - are you allowed to fly above FL290 without and autopilot?
No. Of course not.
I understand the point you are making, but there is
no such thing as something that cannot fail.
The reality is that when the automatics fail, which they can do quite readily, some aircraft can be quite a bit more difficult to operate and more importantly, because the automatics are almost always engaged, some drivers won't have recent practice to fall back on.
And that's the problem. Every day there would be thousands of events around the world where the automatics drop their bundles, and it's simply fixed by the pilots. If you stopped those fixes, it would start raining aluminium.