My brother is a fireman. He says if all they did was put out fires they'd all be out of a job, there just ain't that many fires.
Believe it or not, people used to function, and live quite well, before everyone had a handheld computer that can also make phone calls in their pocket, and they still can. Or at least should be able to.
Ok maybe some of them can't. That would be a personal problem not an issue with some business policy.
Let's face it, some so-called adults just aren't very good at adulting. They need to be babysat and told what to do and not do and "managed" because they won't do it for themselves. If they lack the initiative to be working instead of fartbooking you don't accommodate mediocrity, you take the phone away.