The fact that collaborative document preparation is as troublesome as this in 2022 is a damning indictment on the computer industry. (It's become very good at advertising though.)
It really is puzzling to me that there aren't more and better options in this space. On the one side of the fence you have things like SharePoint or some of the Google bits that are fine for synchronous collaboration on a page or document through a browser, but not very tech or API-friendly. On the other side of the fence you have things like Mediawiki and Dokuwiki that are super tech-friendly, but very manager-unfriendly and not particularly good for synchronous collaboration either.
It surprises me that Confluence continues to be the only thing sitting in the middle of those, and while some competitors have started to shyly emerge (Bookstack, xWiki, I think there's one in progress at Jetbrains), nothing feels like it's really aggressively going after the Confluence market-space directly. Given how many people I've seen comment that they're not fond of Confluence but can't seem to replace it (at least, not until Atlassian forced their hand with the server-license fiasco), it seems like a natural space for people to pursue.
Douglas Englebart must be rolling in his grave at a comment like this https://www.youtube.com/watch?v=yJDv-zdhzMY