Earlier today, I heard a bit on the radio that was of the standard "screen time is destroying kids' minds and making them less social and..." form. Online social norms are still evolving, but I really doubt screens are making us less social.
Here's one data point. Professional wrestling is one of my vices, and when I get to watch, the experience is magnified by real-time online discussions. In particular, I contribute periodically to discussions in the SquaredCircle subreddit. It might seem a bit vapid to enjoy discussions with other pro wrestling enthusiasts, but it really enhances the experience. And not that long ago, there was a Kickstarter or Gofundme campaign for one of the sub's regulars who is dealing with medical bills. I'm sure that wasn't the first time participants in a subreddit or online forum have gotten together to help someone.
Is a world of screens making us less social? I doubt it: it's most likely changing the ways in which we're social with, I suspect, an exponential increase in the number of weak ties that hold people together.