If the ills of social media are, as you say, (and I also believe), caused by the higher-order effects of many individuals "failing to exercise common sense and critical thinking," then who are we to punish?
A phenomenon like QAnon might have been started by a single nefarious person, and amplified by a small group of misinformation lovers, but it's only because of social media's leverage that millions of people have had their moral framework and way of interacting with the world corrupted so heavily.
Punishing the irresponsible was a reasonable solution for all of history where the irresponsible had a reasonable amount of societal leverage. We're no longer there.
Perhaps banning social media isn't the way. But focusing on the humans that find leverage points in the system to amplify bad messages also doesn't solve the fact that the system is designed to maximize ordinary people's ability to create self-sustaining societal doom loops.
Banning guns might be overreach. But banning something that's the functional equivalent of distributing assault rifles to millions of toddlers seems like a necessity in a free society.