The infovacuuming phase of social networks is complete. Training datasets grabbed, social graphs built, biometry compiled.

Now it's very logical to spin that expensive infrastructure down, removing free communication channels which can dangerously synchronize people against the state, and leaving only channels of control: digital ID, CDBC and a white list of governmental "services", all else outlawed.

People of 2010s uploaded their personal data into the cloud because they thought that was cool, people of 2030s will do because their telescreens demand them so.

Everyone who thinks this will stop at "think about the children" is beyond all repair.

Your sci-fi distopia flash fiction is compelling, but not actually on topic in this discussion.

"Think of the children" is weaponized for censorious purposes, but also the harms of social media are well documented (unlike many of the other moral panics fuelled by this phrase). Communication channels are becoming managed spaces, but by private companies not accountable to the electorate, not by the state.

I'm not sure a blanket under-16s ban on all social media is the right answer, but there are really good reasons why people support this that you need to engage with to have a useful discussion here.