>When a switch is damaged/fails, you are out of luck. When a touchscreen is damaged/fails, you use the one next to it.
This is a trivial problem to solve on a physical interface. One solution could be what is commonly used on hardware synthesizers. A shift button or switch. You engage it and all controls begin to perform their secondary functions. You get redundancy for the price of one extra control and a secondary set of labels in a different color.
Also, use of displays to virtually label buttonss is common. In such case you can reassign a control if one fails.
In any case Dragon capsule had physical buttons for important functions as a backup.
The touchscreen frees you from the complexity that comes with giving switches alternative modes, and gives you the mass to have multiple copies of critical switches. Also multimode switches greatly increase the complexity and failure modes, so they need to be done so that if a switch is triggered in the wrong mode its recoverable (eg: the switch for aux radio power isn’t also the undock switch).
When you get to the point of having displays for the switches why not go full touchscreen and eliminate all of that cost and complexity of a bunch of tiny displays?
This is a trivial problem to solve on a physical interface. One solution could be what is commonly used on hardware synthesizers. A shift button or switch. You engage it and all controls begin to perform their secondary functions. You get redundancy for the price of one extra control and a secondary set of labels in a different color.
Also, use of displays to virtually label buttonss is common. In such case you can reassign a control if one fails.
In any case Dragon capsule had physical buttons for important functions as a backup.