The company I work for has a team developing CryptPad, which can be seen as an open source (AGPL) [a], E2EE alternative to Google Docs.
You can edit documents with multiple people in realtime, and the server does not have access to your content. You can self-host of course, but the team also provide an instance [1], and several other people also provide theirs.
It does not have such misfeatures. It has sheets, documents (using an ONLYOFFICE fork running in the browser), Diagrams (using Draw.io), forms, polls, a kanban module, pads, among other things. There's some storage too (a "drive").
It obviously does not provide all the features of Google Docs and its office suite is not as complete, but it can still be useful for a whole host of use cases.
(edit: btw CryptPad has been mentioned in several replies in this thread, it's not us so far but I've sent the link to our chat, they might chime in as well)