Here's one bit of anecdata in response. I've tried to disconnect from social media and get out in the real world. I took an improv class in NYC with about 15 other people, a range of ages & backgrounds. On the last day of the class, a number of the students were asking around for Facebook profiles to keep in touch. When asked, I replied that I didn't have a Facebook account anymore and it was...awkward, to say the least. Like, giving someone an email or a phone number seems much more formal and/or like more of a commitment, I think. Anyway, I came out of it feeling a little disillusioned about the viability of an offline social life. Though this was a group of mid-20 to 40-something people, without the teens you mention.