The real issue is disengaging from the family for huge chunks of time. Except for those that also impair judgement and health (alcohol, drugs) the tool that's used (books, games, phones, other adults) is fairly irrelevant, because the result is the same.

I've seen tons of abuse of cell phones at the park or the bouncer place, though I usually see it with moms yammering the whole time and ignoring their kids, rather than using the data component. I can't say I've ever seen a mom fail to set aside a book when their kids requested their attention, though.