That's the real problem, kids being able to spend unlimited time unsupervised because they have horrible absent parents. Parents shouldnt let their kids have unrestricted time like that. That is one reason why kids suffer in school not because of phones; because their parents aren't involved to guide them in making good choices and forcing good habits.
So we take away the phones as the luddites demand. What fills the gap? Definitely not independent learning. Most definitely not suddenly mindful and present parents.
There is a lot of fear mongering and blaming, but no actual effort to fix it. Banning or removing doesn't fix it. There is a reason that, when absent parents for latchkey kids were huge problems, they didn't simply decree gangs illegal and pat themselves on the back. Communities offered alternatives. But no alternative is being offered here. All the woes are shifted onto the unholy smartphone and internet.
Ya know why predators can find success online? Because shit parents don't parent. A better use of resources would be forcing the parents to sacrifice their phones contingent on spending time with their kids, right?
So the argument boils down to it being due to bad parents rather than evil technology, yes?
That's not the main arguments being used to ban these devices and advocate for more radical plans. Removing access to these doesn't make someone a good parent. Kids turn to other methods.
And to an earlier point in another comment: guess which cohort has explosive growth in smoking at the moment? Not people our age. Teens and young adults of legal age. Gen Z, in particular, is a huge market for that industry now. Cigars and pipes in particular. Vapes are counted separately but are wildly popular.
Banning the sale of highly regulated goods where the state is the official and only legal seller of said good in many states is one thing. We are talking about the internet here, though. And cell phones. And computers. And tablets. May as well put TVs and connected devices on the list, and definitely console platforms.