Texting while driving comes to mind: https://www.nsc.org/road-safety/safety-topics/distracted-dri...
If we all work really hard we can come up with dumb reasons to ban almost anything. Politicians make careers out of this sort of thing.
From a practical standpoint, how about if your car is weaving back and forth they Get checked out.
eating food doesn't leave the same digital trail. if a person crashes or gets pulled over for driving erratically and there's half a sandwich in the passenger seat, there's no way to know whether they were eating while driving or whether they just ate half of it in a parking lot 30 minutes ago.
I don't see how it's any different than eating, smoking, reading, or whatever else people do in their car that makes it harder to drive.