Thomas Shey
Legend
I can maybe partially agree with that.
Though, I have also seen ongoing threads for Dungeon Crawl Classics, (occasionally) GURPS, (recently) Daggerheart, and a few other things.
DCC has a fairly strong fandom and overlaps with the D&D community a reasonable bit. Daggerheart is kind of a new hotness.
I admit a pleasant surprise when something like a GURPS discussion takes off at all, though.
Whether here or in my day-to-day face-to-face life, I've been surprised to find that there are people interested in ttrpgs -and open to playing more than D&D- than expected. A lot of the time, that discovery has come from being more open about what my own interests are.
Oh, you can absolutely find it elsewhere; its just this place is particularly D&D-centric even as RPG spaces go. Which it comes by legit after all, but its a thing you have to account for.