Lots of communties on Reddit have started the process of migrating to different platforms. The federated alternatives like Lemmy have had recent success although I question the complexity of it all in terms of getting mass adoption.
Most of the alternatives seem to be missing the core idea of what Reddit really is (a community of communities). I think first and foremost it's the community aspect of Reddit that makes it appealing.
I've been building a platform called Sociables which is intentionally not just another Reddit clone. We are trying to create an all-in-one place for people to create communities first and foremost and not just posts.
Here's an example of a community: