I would literally not buy a car with this functionality. It is beyond irksome for my passenger to not be able to type on a touch screen while the car is in motion.

Tie it to a weight sensor in the passenger front seat.

Then you just stick a heavy object on the seat to trip it.

Some new cars already do this. It's awful.

This has been the case for some functions for a while. A 2010 car my parents have will not let you enter the settings to do things like pair bluetooth while the car is moving.

In my truck's case, a 2021 Ram 1500 (basic model with a 6 inch screen), you can't change the air position setting without the touchscreen, which is not only a pain, but a little dangerous going down the road. In my wife's Pacifica you can change the positions with a button.

Audi does that at least in 2019 models with some screens that aren't even touch: if in motion, complicated settings are greyed out with some explanation like "not while moving".

It takes quite a bit of hubris to think that just one more regulatory straw will somehow turn the camel into a race horse.

Listening to people when you said you could just add more regulation to solve the problem is how we got here. Cameras were the regulatory easy fix you people put forth when you couldn't stop backing over your kids (was more of a moral panic than a widespread thing but I digress). The OEMs, not being idiots, decided that if they had to have screens to display camera output they might as well make the best of it and use them. Fast forward 10yr and here we are, touchscreens in everything and cars that practically can't be backed without the camera.