The problem with touch-screen is that it is unusable in motion... And that it is slow to use, compared to the big knob. Other thing is that you never know when you are supposed to touch the buttons or the touch screen, depending on the functions.
There also is the problem of durability. A handy lasts between 2 and 4 years, a car is supposed to run at least 30 years...If they use a plastic screen it will scratch sooner or later, if they use a glass one it is a safety issue, and I don't think they can use safety-glass, it does not let the electricity go throiugh because too thick.
But the biggest problem...is that you can't place the touch screen in the driver's vision field.
It must be placed lower to be usable, so it is more distractive in reality.
And more reflecting, whereas a single non-touch screen can be placed deeper to avoid the reflectings, and higher, perfectly in the driver's vision field.
And you can't use a touch screen with your arm comfortable on the armrest... you have to move your arm, to have a precise finger...
For me, a knob with some buttons is the perfect solution, actually.
The voice recognition.. I don't see me talking to my car, honestly
