bluetooth audio is probably all one needs for phone <-> car integration. but carplay/android auto are sadly really popular. So already, your phone can connect in two different ways, just over bluetooth, with cars today. And car companies have to support both. Plus the car must show something on the screen when a phone isn't there, and the rear-view camera isn't on, at the very least on test drives/ showroom displays.

I don't know. On balance, the reality is cars are better overall nowadays, but every aspect of our life has gotten more complicated, including cars.

If you had the option of no screen at all, no rear-view camera, and with physical switches, would you? If this Slate truck gets released, that's the closest, but it's still required to have a rear-view camera/screen sadly.