I'm not sure what's really new here, and if it's such a problem. When I was a kid, there were similar discussions. Kids watch too much TV, play too many video games, watch porn VHS when parents are away. In the end, it wasn't such a big deal.
The entire value proposition of modern computation is about scale and cost. It's the same things, but with much higher quantity and intensity. Something that can be tolerably safe at 1 unit/day may be very dangerous at 1000 units/day. I would be surprised if pre-teen porn consumption has only risen by 1000x in the past 30 years.
Yet humans are the same biological systems.
At what point does it go from entertainment to obsession to something like heroin? There's a point where it does, and we could probably figure out a metric.
It's disingenuous to pretend 'oh there's nothing new here'
Video games had not arrived — when they did they cost a quarter to play. That kind of limited the time spent there, ha ha. Personal computers were expensive so even when they arrived, we of course did not have one.
Porn was finding a magazine in the trash can behind an office building.
The thing that saddens me the most about all of this stuff (the internet especially, perhaps) is that kids aren't out trying to fly a kite any more.
Never thought I'd have so many friends and acquaintances who doubt the world is ball shaped, the moon landing, or suspected 9/11 was an inside job. Yet I do and some of them actually came to these beliefs because of school research papers and debate classes.