Re: To get there ...
The article and your comment hit on a key issue. The 'evidence' is not beyond dispute -- and there are learned people who offer important counter opinions and qualification -- yet Haidt's argument is quoted as gospel by activists and legislators. While I haven't gone to the same lengths, I did spend some time looking up as much data as I could reasonably find regarding social media use and reported mental health problems in various age brackets (sometimes using suicide as a proxy). My take was that the data was largely ambiguous.
Haidt's book is reportedly the single most important source of the Australian social media age ban. The Premier of South Australia (equivalent to a US state governor) was said to be convinced after his wife read the book and proposed the policy to her husband. He then engaged a senior lawyer friend who drew up suggested legal definitions and framework. Given the SA Premier and national PM are of the same party, it then moved from concept to enacted law in record time. No trials, very little call for submissions (that was done very quietly) and the committee thrown together to draw up the 'industry code' was only asked to address the age-check mechanisms - everything else was already chiseled in stone - and, even then, some IT experts quit in protest.
The age-check-ban supporters have become evangelical. They can't be argued with and their fervour is something to behold. The fact that they don't understand a thing about IT doesn't faze them. Most are the usual suspects: the ultra-conservative, religious-right, puritanical and all-men-are-evil-until-proven-otherwise types. They not only gloat over this 'win' but profess that this is just the start, with porn the current step but I expect much more to come. At this point, their spokespeople don't even hide their glee anymore at the prospect of age-gating (and by that I mean identifying) EVERYONE online. And it certainly doesn't help that the security agencies whisper quietly in government's ear that all privacy is dangerous.
Age-ban support amongst the general population doesn't really convey anything beyond a general sense of 'people are concerned with the effects of social media' combined with 'I want to protect my kids' - people have no idea as to what the alternatives might be.
Trample over people's rights? What rights? They've been whittled away to almost nothing.
Having said all that, I'm not a fan of social media. But it has to be a choice, for each adult and for each kid's parents. "Let them be kids", they said. Well, equally, "Let them be parents" and "let them be adults" ... freely. That CAN be done.
Importantly, the question has never been asked, "How do we make the online experience better and safer for kids?" That would have produced a much different potential solution set with, IMHO, a far greater chance of success and minimised impact to the rest of the adult users.