I guess the answer depends on the social media format, right? I think the old school PhpBB forums were peak for interacting with random people online (at least for me). An issue I've always had with things like Reddit and things similar to that is that there's no Avatar and signature to identify people in a conversation. And the forums that I was a part of, a moderator would always pop in to tell people to take it to PMs if there was too much back and forth conversation (or arguments) between 2 people if it got too heated, too personal, and started diverging too much from the main topic.

So, as far as "healthy" goes, I think my opinion is that communities should be more personal and much smaller. Lemmy definitely feels better to reddit and that's likely just due to the size difference and the fact that more of a percentage of us are real people and aren't part of some marketing campaign or karma farming bots. That way, there's more of a sense of community and people can remember your name from past posts/comments. If your "home" on the internet is slow and small, you won't feel the need to scroll endlessly since you can catch up to content.

As far as format goes, I like the idea of a feed (no text limit) where you can see generally what people are up to recently, but there's also topics people can follow that function more like forums. So then the question becomes should communities have artificially limited user counts and see everything (like Path was)? Or should there be a friends list so you only see things your friends are saying and the comments to those posts like facebook? I'm leaning towards artificially limited user counts since it guarantees a small and slow internet "home". And it's gotta be web based, unlike Discord communities.