Computing and testing has come a long way since the Gemini days. We now have aircraft (particularly military fighters) that are literally uncontrollable without the computers.
Those control systems only work within certain preprogrammed constraints. They are generally incapable of handling unexpected situations outside of the design limits.
Computerized fly by wire systems still depend on a pilot in the loop, especially in the case of a mechanical failure.
So let’s say the airplane gets damaged, and one of the flight controls is no longer available. A legacy airplane would still try to use that surface because it doesn’t know any better. The F-35 digital flight control systems will say, “That surface isn’t doing much for me anymore, so I’m going to have to compensate by using some other things. Maybe I’ll have to move them a little bit more to get the same effect because the pilot still wants to turn left.”
