What's the expected online experience of minors ousted from social media by surveillance state age-ban (identity-gating) laws?

(Age-restricting social media is primarily about de-anonymizing online activity [by requiring each online user to submit legal documents and/or biometric data to link to their online behaviour] as a means of social control, eg, to eliminate future anti-fossil fuel organizing.)

That said and, hypothetically assuming a teen can't circumvent the age restriction, what would the average 15 year old's online experience be like? What would they do/ see/ be exposed to? I'd expect most would spend time on social media if they could. So absent that, youtube (if somehow not categorized as social media), gaming (if they're into that), and the 'AI' baked into common searches and browsers primarily? Is there 'underground' social media that the average teen would access?

I don't think kids of that age would have been taught to run actual searches, examine sources, and read content from primary searches.

Is a potential impact of this legislation to reinforce the next generations' use of the 'AI' and the closed, corporate-controlled internet big tech wants (ie, walled off gardens, pay-to-access information, etc.)?