@koimoa@Weeble@whut lj was a corner of the internet, Tumblr and then Twitter were increasingly centralized and giving said groups more power.
Tumblr seems quiet because the porn ban was the site being declared a suicide with two shots to the back of the head and tied to the railroad tracks.
The closest replacement is cohost UI wise, but the code sure as hell isn't open, it's a walled garden by design, and the community isn't diluted but rather a microcosm of tumblrs finest.