Years ago when I was working in IT at FoMoCo I recall seeing a piece of paper on an office bulletin board outlining how they had managed to save like $40 on the production cost of a Taurus, a vehicle that at the time was about $20,000. Those savings were the result of multiple sub-$1 to several dollar cost savings tweaks made between production years.
Ford has built something like 8 million Tauri, save a few dollars on each of them and it adds up to real money, like enough to redecorate the executive cafeteria.
There are also reliability expectations. If I need defrost because the windshield just fogged over, it better activate when I turn that knob on my sixteen year old car. And so far, it always has.
My favourite feature of touchscreens in cars is when you try to click a button but go over a bump[1] so your finger misses and you press something else. Genius.
I do get that touchscreens allow manufactures to add and remove controls though.
Rolling out UI changes for self-driving cars, like getting rid of the, knob behind the wheel, will help with safety no end.
1. Not sure what the bump was, probably the neighbour's kid or dog or something. Too busy trying to get the latest Smartless. That Will Arnet, what a card, etc, etc...