Richard Stallman has said that social media sites don't have users — they have useds. The primary reason for sites like Facebook to exist is to generate revenue for the company (obviously), and they do so by using their webpage as a terminal for advertisements. To maximize revenues, users (useds) are incentivized and otherwise manipulated to stay online, giving as much eyeball time to the ads as possible.
Much has been said about how social media companies achieve this maximization from a psychological point of view. Dopamine-inducing "likes", targeting users with news/messages that will cause strong emotions (such as anger) to keep them engaged, things like that. But what is the real technical innovation that has made social media so irreplaceable in many people's lives, even those that are rational enough that those previously mentioned "incentives" are negatives for their lives?
The basic functionality that a social media platform like Facebook offers its users is a non-intrusive broadcast to all your friends and family. Now, the "broadcast to all your friends and family" is supposedly the "social" part of social media. But what do I mean by "non-intrusive"? I mean that, on Facebook, your life updates don't necessitate a reply, don't start personal conversations (at best, just a stream of "Congratulations!" or "Thoughts and prayers..." comments), and it's not rude to just completely ignore them.
Before, to announce a new baby or invite friends to party, you had to manage your own contacts list.
You would send postcards from vacation to a few select people, now you just post the best pictures you got taken of yourself to Facebook, maybe with a witty caption, and the best one of them all might even be worthy of Instagram.
Instead of discussing clever and/or silly ideas with your buds and a beer in hand, you post them on Twitter, hoping for retweets and likes rather than a conversation partner.
So while social media has made all sorts of social interactions much more time and energy efficient than phone calls, email, snail mail, and real life conversations, it also has replaced all these social interactions with much less social alternatives. Additionally, we have to realize that most of the content on "social" media isn't even social — it's marketing!
Any platform that allows non-personal broadcast — like Facebook pages or any account on a asymmetrical follow platforms (Instagram, Twitter) — becomes a marketing platform rather than a social platform. Even without the concept of promoted posts, Instagram has influencers and paid posts. Twitter is all about thought leaders preaching their takes, politicians jumping at each other's throats, and celebrities gossiping out in the open. TikTok perfected the promotion algorithms to launch the careers of thousands of self-made 5-second comedians and snake-oil salesmen.
"Perfecting the promotion algorithm" is something you do to build an advertising platform, not a human social network.
Stop calling it social media. It's marketing media.