I think the car manufacturers will mitigate it with more voice control rather than go back to buttons.
Could well be right. I'm a bit of an old fogey and do 'worry' about touch screen everything. That said, my passengers know to keep quiet when I approach a junction as I can't process what they are saying and concentrate on the junction.
Hey car, play Talksport would be far safer (as long as , in response it swerves me into the nearest tree for even suggesting that).
The horn I expect must remain a 'button' , arguably the headlamps so you can 'flash' people ,even though you aren't supposed to.
Everything else I would think could react in a timely fashion, even signal left , obvs not for drivers of german cars
--edit-- the most beneficial one for speech I reckon would be the ability to set the sat nav via talk, admittedly rather than program it before you set off which really should not be an issue.