Sure the old social there was the kid with porn mags and cigs in his treehouse, but you were never at his house 24/7 and that limited exposure almost inoculated against long term addictions and you experienced it with peer input. Parents would eventually isolate you from those bad elements due to neighbors gossiping and the like.

The new social is your neighbors don’t even know you have kids much less who they are talking too because they are on their phones and kids don’t have peer interactions because you don’t let them outdoors fearing people will report you are exposing them to a dangerous world.

Tech should absolutely have filled that void with a simple age appropriate pediatrician approved on/off with advanced controls available for those that want to tighten or loosen the reins.

I do not have kids, but would envision something like under 5 have no advertising and no network connection without a manual unlock, under 9 should only have access to content with heavy moderation and manual review of advertisements with only approved social contacts and parental alerts for potentially problem content, under 12 restrict unapproved contacts within local school district with problem content blocked with a manual unlock for a set duration, and for under 18 just do an machine learning scan on content and the kid can choose themselves if they want to reveal it with on device warnings about adult content, bullying, scams, and grooming with suggestions to discuss with parents.