FWIW, I do think there is something damaging about screen time especially if it is just passive consumption ( brain is a muscle; if it unused, it will grow weak ) so I am personally trying to limit it. I already spend so much time with it at work ( and until recently, at school ). I do allow myself some guilty pleasures, but I treat those similarly to the way I treat ice cream or sake. It is something of holiday from reason.
edit: HN is probably a giant exception to that. It seems I spend a lot of time here. Maybe I can rationalize it as 'HN is not guilty pleasure? I get to argue with people over stuff I normally would not?'
I guess my main point is that the main responsibility lies with the parents and it kinda sucks, because at least 'in my days' my parents didn't have giant corporations working on keeping my kids glued to their device. All I had to deal with is arcade addiction.. and that.. my parents solved ( with me crying all the way ).
Some do, some don't. My 2nd grader is happy to self regulate. My 4th grader will however spend 12-14 hours/day online and as the screentime accrues, become more likely to annoy, torment, and eventually act violently in response to perceived transgressions.
We're otherwise a no tv, no videogame console, no tablets house. Not because we've decided not to have these things, but because a half-a-day binge has resulted in a kiddo rage-destroying the device at some point and not having the broken device any longer is a natural consequence to that behaviour.
So no, I dont think all kiddos can typically learn to self regulate.