[kawfey]

They really should.

Even commercial and fighter aircraft -- which have human-interface requirements of incredible depth and complexity -- are transitioning to large touchscreen displays. ALL of which require physical boundary buttons and knobs as a redundancy for touchscreen controls.

In fact, controlling the screens via buttons are the preference for many pilots since accurately fiddling with touchscreens during turbulence, pulling Gs, evading missiles, while being task-saturated etc is very hard to do, but doing the same with physical buttons is far more reliable. Button-pushing tasks can be performed from memory in the blind (or while not looking) (a.k.a. "memory items").

There's always been a dichotomy in human-machine interfaces between airplane customers (airlines, charters, governments, and militaries) vs. their own pilots. Airplane builders have to keep up appearances and look cool by putting in putting in flashy, futuristic features like big screens and AI, and ditching old button-laden displays and the "old way of doing things." It too often disregards the needs and wants of pilots and "human factors" engineers. Fortunately, safety comes first, so the buttons and redundancy must stay.