I think there are some people here with a slightly old fashioned view of social media, and that is me speaking as an old git. Look at the way younger people use it.
We have all, always, however much we have denied it, and however matter of fact we feel, developed images of ourselves and our relationships which we project to the outside world.
For many younger people, there is a now a virtual social media image alongside this, curated and sculpted by them. See your teenagers interacting with this, and you see how important it is to them, (not all, my 14 yr old son seems relaxed about his, my partner’s 14 yr old daughter less so).
For me FB allows organization of MTB stuff, staying in contact with people who I haven’t ridden with or skied with for a while. It also allows me and friends to post what are basically postcards. And yes, for my partner and I who have only been together for 15 months, to share where we are in our lives together with friends.
And I see some stable loving long established couples doing the same.
What I don’t get is the people who post platitudinous bullshit posters, and all the “share this if you have ever…” toss. 😈