(Using Lemmy+Mastodon as an example) Lemmy has the concept of "communities" - subreddits, basically. On Mastodon, you can follow a Lemmy user and see their pos

(Using Lemmy+Mastodon as an example) Lemmy has the concept of "communities" - subreddits, basically. On Mastodon, you can follow a Lemmy user and see their posts+comments exactly as you'd expect. And you can follow a community too! To Mastodon's point of view, the community is a single user that "boosts" (re-tweets) every post and every comment made within. So following a moderately active community from Mastodon will absolutely flood your feed with 100% of the community's user activity. Meanwhile, Lemmy doesn't do direct messages or use hashtags as a first-class feature. So if a Mastodon user tries to DM a Lemmy user, or a Lemmy user wants to follow a hashtag, they're out of luck. And again, there are other Fediverse apps with even different models than these. Gitea, Forgejo, and GitLab are going to adapt ActivityPub to all federate with each other - this is a huge win, of course - but would we expect someone to make or review a pull request from their BookWyrm account?