- The mandate is for rear visibility. Car manufacturers choose to implement it with the back-up camera. Beyond that, it's obviously safer to be able to see everything behind the vehicle.

- My vehicle has a backup camera with a screen, but has physical buttons for all controls (A/C, audio system). There's no reason cars can't have both.

> The mandate is for rear visibility

Specifically, 10 feet by 20 feet directly behind the vehicle. I'm actually curious how this could be achieved with only mirrors. That's a pretty big swath for anything with a viewpoint where the driver is sitting.

> My vehicle has a backup camera with a screen

Early implementations just used a screen in the rearview mirror. No need for any kind of infotainment screen.

When it already has a screen it's much cheaper to get rid of the buttons then. The screen as a requirement is priced in whereas the buttons are not and thus cut.