[kgermino]

In theory those screens are regulated to be safe to use while driving - my car for example has a lot of more complex features disabled while the car is in gear - while the phone does not have the same safeguards.

Whether those safeguards are effective is a separate, albeit critical, question

[tremon]

But that's an equally bad solution, because usually the touchscreen is located on the center console and can also be operated from the passenger seat. Disabling touchscreen features is needlessly restrictive when there are two people in the car.