Just something unsexy that works and can stick around in the same form because the owner is a curmudgeon with out any dreams of grandeur.
Perhaps the could never have happened to social media though because it was too hot a space.
Everything else seems doomed to get caught up in this race to capture a billion eyeballs and wallets.
This sounds a lot like Nextdoor. The results haven't been pretty.
It worked reasonably well for my university when I started 25 years ago, but it deteriorated quickly during the yearly 2000s.
We also had forums, blogs and RSS. All technologies when combined provide a decentralized social media like experience. I think it was a healthier approach, but more segmented. Modern social media attempts to fit everything into a framework. From a financial perspective, it seems to work, but socially I'm not convinced.
One of the thing that have impressed me is how willing people are to express repulsive behaviour, under their real name. You'd think that Facebooks real name policy would make help regulate behaviour, but it truly doesn't.