Manufacturers want to streamline their interiors to make it look more spacious and put more cupholders. I think removing physical buttons are a bad idea, they are just making things more difficult and expensive to repair when things break, especially when if your HU hangs and suddenly you have no AC control.

It's unnecessary and comes off as a dick measuring contest (My car has less button than yours) at the expense of consumers.

Some simple mechanical functions such as handbrakes should also stay mechanical.