I dunno, I have a teenager, and they have friends. I have a teenage niece, plus dozens of little cousins with devices.

While it can seem like that constant access is a negative, and I've seen a study somewhere about it being really bad for vision over time, what I don't see is anything worse than what TV, gaming, hobbies, or phone calls did to my generation.

The key difference is that the kids can do all of that with one thing, from the couch. So, with a bit of willpower to enforce exercise, and limits on time to allow for family time, I think all claims about harm (unless there's good data the back up a claim) are no better than the bullshit about gaming, or arcades, or heavy metal, or d&d, or any of the other stupidity that has been claimed to be ruining kids over the years.

Kids, teenagers in specific, can require a bit more effort to shift their attention when they have a device in hand, this is true. But people don't remember how damn pissy teenagers got when being pried away from a TV. If my grandparents stories about my parent's generation are true, even before TV was everywhere, teenagers were assholes about shifting attention from their focus of the moment.

From what the one great grandparent I grew up with said, my grandparents' generation was different only in access to distractions. And, for the most part, for a kid back before TV existed at all, radio and books were just as difficult to pry an ear or nose out of.

Now, I will say that most teenagers can end up boring as fuck because they get lazy about using/doing non device things. When every interest is tied to absorbing entertainment in some form, you end up with monomanias in cycles that I don't recall from being a teenager among teenagers. Not that they didn't exist, but you'd see more diversity in interests on average. But, have you seen fucking adults now? It's getting harder and harder to find adults that aren't locked into their device in one way or another. Adults are boring as fuck too, just in different ways, and often were in the past.

Anyway, point is that until there's good data compiled, the whole "kids these days" is just as bullshit as it always has been.