Only auto-braking among those has been made law, and it won't take effect for atleast 4 more years, provided it stands intact that long.

Source? Considering that not all cars for sale have all of those features, I'm pretty confident in saying that you're wrong.

Back-up cameras are required by law, so that requires a screen, but the law does not require that screen do double-duty as an infotainment screen.

Perhaps.

But there was a time they weren't required by law, and people still managed to drive.