My only experience with touchscreen cars is with the Model 3. You don't need the screen for operational stuff needed for driving. Off the top of my head, these are all on the steering wheel/stalks:
- Blinkers
- High beams
- Gearbox
- Climate control temperature up/down
- Cruise control enable/disable, speed change
- Media volume, media next/previous
- Phone call answer/hangup/volume
- Windshield wipers
On the next Model 3 version, they are moving the gearbox controls over to the screen. I have my doubts about that, but I'll complain once I have driven one.