Social networks most important metric is "engagement" number of minutes spent on the site. And turns out that it is human nature to engage with content that it's "dangerous" so the social networks have optimized to show divisive content.

A free social network, will work to improve the happiness of their users... Which will include measures like limit the amount of hours you want to spend on the site itself. (Like HN does by the way)

Or like I'm in NYC today, who wants to meet? Let's have a real interaction