Because the interface is delivered by screens controlled by software what is displayed can be simplified to suit anyone’s tastes and mental abilities. Totally customizable and I am sure cars of the future will offer a ‘Jitterbug’ option without “all those confusing buttons and features.”
Ouch! ;) Thing is, though, 99.9% of my driving consists of keeping my eyes on the road/idiot drivers around me, operating the steering, clutch, gear shift, and brakes. Not that that is mentally taxing, it's mostly "muscle memory" after so many years of driving. The old going from point A to point B routine...
Secondary controls I prefer to have accessible as simply as possible, and mechanically tactile beats a touch screen by that metric.
There just are not that many secondary controls I *really* need to play with while driving. My current car is already over the top with, for example, an idiotic climate control system that lets you adjust temperature in 0.5° C increments. What was the last time anyone driving a car thought, oh, 22.5° C feels a bit too warm, better change it 22.0° C? AND there are separate controls for the driver and passenger seats. As if that does crap all in an enclosed space of a few dozen cubic feet...
For some things, simpler *is* better. Especially for those of us with lesser mental abilities. :)