I think the problem is that people are lonely in ways that the medium can't address well, but does address to some lesser degree, so it elicits lopsided engagement. You're this whole person but people only ever react to this quirk or that one because those quirks come through better online, and over time those two quirks become a larger share of your personality. We end up with things like looksmaxxing--because pictures go online well, and it happens at the expense of whatever other characteristics of that person don't go online well.

I've been imagining a social medium which finds temporary peers via one of your phone's radios--so it broadcasts and gathers rotating public keys as you ride the same bus with people or share an elevator with them--and then your feed contains whatever they're posting, but only for 48 hours or something (unless you decide to make the connection permanent). That way when you see something cool in your feed, you're well positioned to go be social in meatspace.

Like I get why you don't bring your guitar on the bus, same reason I don't bring my drums on the bus, but if a few hours later I saw a video of you making some music I might be like "hey lets get together and jam" next time I see you.