There's an even simpler solution: ban free social media. Require each platform to charge a minimum of $x/user/year.

You remove kids by default (no credit card/bank card), and the focus of product managers is less on driving addictive browsing, and more on driving renewals (presumably through quality features, content, and fostering community).

The customer is no longer the advertisers (or shady Governmental data scrapers), but now the users.

Look at the generally higher quality of Netflix content compared to free-to-air TV.

You could apply the same regulation to other addictive products: p*rnography and games. These categories would also improve in quality, be less exploitative, and become less available to children, if a minimum payment was required for access.