> Bluesky solved the DM case by adding E2E encryption using the Signal protocol

This is patently false. Bluesky DMs are not E2EE, they do not use Signal.

Germ is the MLS based system that a few bluesky users are on, but it started separate from ATProto and has had account integration to atproto added on later. The folks behind that are a separate entity from Bluesky. I'm not keen on this setup, I'd prefer an MLS scheme where there are more controlling entities of the servers.

I agree E2EE chat is not the foundation for a Discord alternative and that Colibri has poor messaging and understanding. Communities need permissions, UX needs visibility into the data for things like search. E2EE has unsolved scaling problems required for real world communities.