In the early 2010s there were definite upsides. Before social media there was corporate media, which is almost always controlled by the rich and powerful, or in many places outright by the government. Social media at its core is media by the masses, so when early-ish social media broke the mold we got a lot of people striving for positive social reform, like Occupy Wallstreet, the Arab Spring and the Hacktivism that happened under the Anonymous umbrella. Most of them got successfully snuffed out, but had social media continued like back then a lot of good might have happened.
This changed about 2015 as the weak and powerful alike learned how to manipulate discourse of social media, and bots started flooding most platforms.
Right now the biggest "positive" effect I can think of is that people are less idolized. Before social media you only saw the good side of most public figures. Now that we get to see a lot more unfiltered thoughts from them we get a much more nuanced picture of everyone, both their good and ugly parts. Not sure if this is a positive overall, since lower expectations also means we don't hold people to as high standards. I guess we'll see how this plays out as society adapts
I've found social media use a good yardstick for identifying lunatics and avoiding them. Since I stopped hanging around with anyone who uses TikTok, Facebook or Instagram and LinkedIn, I seem to have made better real life connections with people who aren't lunatics.
I do think the ecosystems that developed around mobile tech will be viewed as the cigarettes of our era.
However this account hardly contributes to that conclusion since it's so small a study without any controls, at least according to the rewrite. I really wish the link to the original poster wasn't broken