Talking while driving is a moving violation
Like speeding or running a stop sign you have to be caught doing it. If I admit driving 110 mph last night the cops can't show up and give me a ticket, but they could stake out my garage and follow me around to see if I do it again tonight.
Some states still don't even have talking/texting while driving as a primary violation, meaning cops can't pull you over even if they see you doing it, unless you are doing something else illegal that gives them a reason to pull you over.