An extra annoying problem about social media for me is that while I can make most of the platforms give me a chronological feed of content authored only by people I follow, most other people see mine in an algorithmic feed. This includes people I have zero social connections with. For example, I just gave up trying to discuss politics on Twitter, because every time I post anything political, that tweet ends up in the feeds if hundreds of people who hold the radical version of opposite views, with predictable results. And there's nothing I can do. I can't opt out of being recommended.
What's left?
Hacker News itself is all about reading articles, and then discussing the articles with others. "If you had to reduce it to a sentence, the answer might be: anything that gratifies one's intellectual curiosity."