Perhaps this is more the responsibility of the parents who give their kids the devices and allow unfettered access to the platforms than it is the platforms themselves.

Or what the heck, sue whoever has the deepest pockets.
https://www.theverge.com/2023/6/2/23746904/maryland-school-meta-google-tiktok-snap-lawsuit

Maryland school district sues Meta, Google, and TikTok over ‘mental health crisis’

A school district in Maryland is suing Meta, Google, TikTok, and Snap over the “mental health crisis” that social media companies have caused for kids.

The Verge