Talking about and being from that AoE games generation, I think a big part is the absence of any restrictions and incentives to stop. Only very few of my friends back then had unrestricted access to videogames or even TV. And even if they did, there is only so much time you could sink into a sp game before you might want to do other stuff. This even more so for non strategy games. There was only so much you could get from a Super Mario game. Internet access was even more restricted. And they would have been alot stricter if they had known what was out there. You might have heard the web is a fucked up place?
With even smaller kids having a smartphone and constant high speed access to the web, of course they are stuck to the screen. Its a never ending source of keeping you entertained and hooked and you might remember, that being a kid can be boring as hell. With the phones so affordable and everyone doing it, it was kind of inevitable of a development. I think we are witnessing the fallout of that development. With kids stuck to screens and as a reaction the ever increasing demand to make the web more childproof to at least have less of a bad conscience if you let your child have unrestricted access.
I dont think individual parents are to blame though, being a parent is tough and you dont want your kid to be the only one without a smart phone. Neither do I think an all or nothing approach is any more sensible. As always the dosage makes the poison, which is why I think approaches like in french schools are reasonable, who banned smartphones inside the school. Having it established, that there are restrictions to smartphone usage might help parents to establish restrictions as well. However, it all boils down to the question of what is appropriate content for children, and whether the internet is intended to be such childproof content. The answer might simply be no, in which case the only real option would be a second child proof web. Sure, it would be close to impossible to enforce, but so is the ban of giving alcohol to minors. Kids will get their hands on a beer sooner or later, but such bans are usefull enough to not give them easy enough access to drink daily.
But thats something we need to decide as a society. We might decide on something else or keep everything as is, but at least we would have made a decisions. Because we shouldnt kid our self, at the moment we simply keep ignoring the issue only interrupted from short periods of senseless actionism. The availability of smartphones have introduced new circumstances and it is no suprise, that without intervening, they had a clear effect.