They are already mostly segmented off from their friends after school hours. They have killed off one of the final mediums for interaction and are preventing interaction with the rest of their generation's culture. They're also narrowing their world view to be more controlled by the state.
Hasn't that been the case for thousands of years? It's not like they can't see each other after school hours... I know i used to. And i still see my friends after my workday. I have much deeper connections with the 20 people i see in real life than the 1000 people on my linkedin profile.
Do people thrive more in their mental health when they are supposedly 24/7 accessible? Is it necessary? Is it wanted?
Actually this is a separate problem. If you look at the work of Jon Haidt who promotes the kinds of measures we're talking about here, it's only half the story. The other half is that we have become ridiculously overprotective in parenting in recent decades. Kids need independence and the ability to hang out and play with their peers away from direct adult supervision. The goal isn't to take away the internet and leave kids with nothing, it's to bring back the real-world contact and relationship-building.
No, we need to turn it WAY up. We circumcise AKA male genital mutilation to hundreds of millions of male children all across the world, including much of the USA and Australian populations.
That’s just one tiny example, and no one is calling for circumcison bans simultaneously.
Letting the mutilated children have some social media is the least the state can do for them. Australia is a tyrannical hellscape.
Not being exposed to social networks for a few years is no way comparable to depriving them of bodily autonomy.