An issue is that the definition of 'social media' seems to be 'websites where people are toxic'. What I mean is that websites that share a lot of similarities with 'social media' don't count as social media, because we like them. People don't think highly of Twitter, Facebook, Reddit or YouTube, so those are social media. Web forums, slashdot and HackerNews? Those are good websites, so they're not social media. I don't think of HackerNews as social media, at least. But if one news aggregator with comments is social media then aren't they all? Is 4chan social media, despite having no persistent identity?

When I think about the problem with social media, I think abstractly. It's a broad social problem. But if I think about the problems I've had with it personally, they're different problems than the ones you hear about. I don't really care about 'toxicity'. I'd rather someone was directly rude to me than that they downvoted my comments without explanation. I dislike euphemism.

I agree with you that social media does not seem to be about cultivating friendships. But was it designed to be? I think this again gets into the issue about the definition. Social networking was about digital friendships, at least in some sense. Facebook even calls your contacts 'friends'. Being able to easily contact someone you haven't seen for a decade, organise reunions, etc. That's social networking. But the way some people use Facebook is more like a social media website: not to interface with friends, but to follow news organisations and get into arguments in the comments. They use it more like someone who uses r/worldnews on Reddit or someone who follows mostly news organisations on Twitter.

On the other hand, you have people like me. I unfollowed almost every page I was following on Facebook. Now I just see (infrequent) posts from friends and family members: pictures of their kids, weddings, etc. Family notices posted about births, deaths and marriages. I haven't seen a 'status' posted by someone on Facebook that was just an ad-hoc musing since high school. I use FB Messenger more than FB itself. I don't use Twitter, but if I did it would be for microblogging as it was originally intended about things I was working on, not for getting into arguments with people about politics. I doubt anyone would read it, so I don't bother.

I don't know why those platforms devolve into arguing but I suspect it is not actually the algorithms that people like to blame. I think people like to argue. The shield of anonymity allows them to do so. People used to do this on old web forums back in the day. They try to do it here, where the algorithms punish it severely. If people could get into ferocious arguments in real life where they were shielded from anonymity but could use whatever words they liked and there was no chance of physical escalation, they would do so there too. People give Facebook as a counterexample to the idea that it's anonymity, but I don't think the people that argue in comment sections on Facebook ever expect to meet the people they're arguing with in real life, or expect any of the comments to come back to them in real life, so the cloak of anonymity is still effectively there. It's consequence-free and it's escalation-free.

The threat of physical escalation and long-term social consequences seems to moderate people in real life. The old rule that you oughtn't to discuss religion or politics at family gatherings is evidence that without such a rule, people probably would do so and it would cause long-term negative consequences for them socially. What's the solution online? I don't know that there is one. People will escalate verbally because there's no limit to it. Physical escalation IRL is (maybe controversial?) kind of similar to nuclear weapons: very bad, of course, but the threat of it actually reduces the occurrence of lesser (but still detrimental) conflict.

Part of the problem with moderation is that it is very hard to do well. For example, moderating for "decency". What is decent conduct depends on the person's perspective. If I have a strong moral objection to something you are talking about, then to me you saying so is indecent. Palantir is a controversial example but I think there was some controversy about "just talking about technology" when they are involved on here or on Lobsters. On the other hand, to them bringing up political disagreements with how the technology is used is not decent and kind, but introducing politics where it isn't needed. I'm not really sure how you square those two. Or to use a different example, to some people it is indecent and unkind to suggest that diversity, equity and inclusion policies do more harm than good to workplaces. So if there were an HN thread about a tech company changing their DEI policies, do those people get to decide that any anti-DEI comments are unkind and should be moderated away? For the people making them, they don't feel they're doing anything wrong. Moderation should, in my view, always result in a reasonable person thinking to himself "I'm not sure I agree with the decision, but it is a decision that a reasonable person could reasonably have made in all the circumstances." If that's the case, then at least people don't feel hard-done-by.

Part of the issue is that online there doesn't seem to be as much scope of agreement on what is and isn't acceptable, other than illegal material like child pornography, and "NSFW" except in places where that content is clearly allowed. But websites where people can make comments vary between those where you are permitted to directly insult others using slurs (like 4chan and to some extent Twitter and Reddit depending on the moderation policy of the subreddit, where you are expected to just deal with it) all the way to websites where any kind of unkind comment is against the rules (like the Rust subreddit, for example, where the result is a different and more euphemistic kind of toxicity).

Moderating fairly is difficult, and kindness isn't always a good thing. When you use a metric, you end up working to the metric rather than the real goal. If you moderate to require everyone to be nice, what you end up getting is people writing things that are superficially nice - they don't use nasty slurs and they don't directly say anything nasty at all - but they are toxic in their own way. You only need to look at the discourse around the recent Rust controversies to see this: everything is communicated by people saying they're "uncomfortable" or "uneasy" about things rather than saying "I think this decision was bad and that people operating behind closed doors while preaching openness are dishonest bad-faith actors that should leave the project" which is pretty obviously what they're actually thinking, IMO. I think this euphemistic way of working is particularly American, but I don't want to overgeneralise.

I'm sorry, my comment doesn't really address all of your points. All I can really say is that I agree that it's a big problem and it's not clear how to solve it. The obvious solutions like "make everyone be kind" don't work, but neither does not moderating at all for obvious reasons.