Further, having an interface that is problematic for driving is not problematic ONLY for driving. I use music services while exercising, either outside or on an indoor machine. I'm bouncing around, I don't want to stop, and it's hard to hit these tiny little UI elements while I'm moving. The UI for listening to music while exercising (or driving) is actually far inferior for most touch screens when compared to an old iPod with click wheel or even an old Sony Walkman cassette player.
Add in the fact that CarPlay on my late model car is incredibly glitchy. The situation is so bad that I wonder if I would be better off putting music on USB flash drives and plugging those into my car.