My instance has it. It's local communities are focused on a specific niche (books & writing) so it might not be your cup of tea though. But basically when setting it up you specify which instances it pulls from, how often it pulls and how many communities it can pull at a time. You can filter specific communities and instances, and it'll automatically ignore instances you've already defederated from. By default it pulls the top /all posts from the instances you specify. Mine pulls from a couple big instances and smaller niche instances as well every day around noon to get a solid diverse amount of content. You can also auto disable NSFW communities from populating as well. It's basically the equivalent of telling the bot to go to the front page of each instance, seeing the top posts of the day and pulling from each community that's there to check if it's federated into your instance or not and if it isn't itll pull it in for you.

With the way lemmy functions if a problematic community starts hitting /all an instance admin can just remove the community and it won't federate into the instance anymore. Ideally there would be more granular federation options in the future, but with the things that the seeding bot does now it works pretty well.