Jurisprudence has, over the ages, slipped from addressing actual wrongdoing to addressing the *potential* for wrongdoing.
Such laws give the police an all purpose excuse to pull people over. If the cops don’t like your looks, you look out of place, you’re going too slow, there’s something minor wrong with your car, and other things like that, you’re pulled over. Now it’s “distracted” driving.
But cell phone usage is unlike many of the other “distractions” that are often cited, like eating, talking to a passenger, changing a radio station, etc. All of those things can be postponed if a road situation requires it.
But a cell call or an incoming text is impossible for many people to ignore as if somehow a call going to voicemail, or a delayed answer to a text, is some sort of social blunder or an insult to the other party.
People like these:
https://www.youtube.com/watch?v=nYgTM1pPjKQ
It’s funny when these cell phone zombies do stupid stuff to themselves, but it’s not so funny when they do it while driving.