I shudder thinking about what would happen if a touch action on the touchscreen would get stuck

The Dragon Crew has physical backup controls. The touchscreen allows for a more interactive UI that you can try out here:

https://iss-sim.spacex.com/

But the controls themselves have physical buttons in addition to the touch screen.

Also all systems have triple redundancy.

There was a decent amount of concern within NASA on the touchscreen design, but the contract type tended to force those discussions to the sideline. In the end, NASA wanted a ride and not to drive the design.

Edit: for those wondering, this is not hearsay or speculation; it is from direct experience (albeit 5+ years ago)