After Elon Musk's acquisition of Twitter, many scientists report the platform is no longer suitable for professional use. A recent survey indicates that researchers are increasingly turning to Bluesky, which they view as more useful, welcoming, and aligned with their goals.
There’s a few, not too many at the moment because most people just host a 1-person pds.
I can’t find a post I remember seeing with a bunch of them listed, but I can say that I remember that blacksky runs their own pds and relay, and it’s open signup