Hasn’t virtually every single study ever performed on the subject found a strong, direct link between unhappiness and social media use?

From what I've seen, the answer is it's complicated. On avg, you're right, and it prob does cause unhappiness and mental health probs. But there are unique situations where it can be helpful. Ex, people who do not fit norms of thier peers, and find healthy connections with others more like themselves. So it has no single, simple universal answer.

The algos, esp on big tech social media like FB, IG, TT, X, etc, are very much designed to make you unhappy and outraged. Even the data scientists who designed the algos have testified to that fact before the US congress. B/c anger and outrage is the most powerful way to make you engage more. TT's internal research shows the more you use TT, the more probs you have with cognitive skills like memory formation, empathy, and anxiety.

Ofc, the harms of social media doesn't mean these bills are the right way to handle that. I believe we have a prob. But this is not the right solution.

To a large degree, yes, but blanket bans on social media use for minors will fail for multiple reasons.

1. This has already been the case in Australia, and the latest numbers indicate that a vast majority of youth still access social media via black/grey market account purchasing, VPNs, and other methods.
2. The ban doesn't include some popular platforms like Telegram, which arguably provide a more risky experience, due to it being a popular platform for criminal activities.
3. Taking away a huge swath of social platforms from kids without providing any constructive or healthy alternatives will mainly encourage destructive behaviors.

If that is so, which I do not know, the only logical explanation is that people who are already unhappy, for unrelated reasons, are more likely to need to find at least some happiness in their lives by participating in online communities.