Mbin support quite a lot of activitypub protocols, including PeerTube even.
Mbin also support microblogs like Mastodon, all within the same web frontend. Mbin has quite an impressive moderation tools by now, while we are still improving moderation support. Mbin has a very different user-interface, which I like much much better than Lemmy UI. Mbin also has tons of user-side options to fine-tune the UI, like Infinite scrolling, moving the menu to the left-side, different themes, page width settings, sticky navbar, and so much more! Mbin is developed by a developers who aren't Lemmy core devs (I'm not going into more details here). Mbin has a very complete API, allowing app developers like Interstellar to develop apps around Mbin instances. Mbin is still in heavy development, we implement tons of new features, frontend improvements and bugfixes every single day/week. Mbin embraces the C4 specification for contributors, meaning that every person could become a core developer.