Obviously I can't say if this is universally true, but it is most certainly true for me. I have CarPlay, and I do my damnedest to control it with Siri. It always feels incredibly dangerous to use the touchscreen.

Because of the problems I have with Siri, I end up using the touchscreen much more than I'd prefer. My latest defensive habit is to queue up enough audio for the trip and not touch it again until I arrive.

I would definitely prefer hardware buttons.