Self hosting seems to consist of "set up nextcloud, set up collabora, click the integration button" https://nextcloud.com/blog/how-to-install-nextcloud-office/
Or just `sudo docker run --init --sig-proxy=false --name nextcloud-aio-mastercontainer --restart always --publish 80:80 --publish 8080:8080 --publish 8443:8443 --volume nextcloud_aio_mastercontainer:/mnt/docker-aio-config --volume /var/run/docker.sock:/var/run/docker.sock:ro ghcr.io/nextcloud-releases/all-in-one:latest` if you follow these instructions: https://github.com/nextcloud/all-in-one
As for :latest, that depends on the push policy of the container owners. NextCloud only pushes stable releases to :latest so it's probably fine. There's no reason a :v123 tag would be any more or less secure than :latest.
CryptPad just seems more secure compare to Nextcloud.
If you want a full suite, the German government has been working on integrating and packaging a whole open source productivity stack: https://www.opendesk.eu/en
Their file storage solution is Nextcloud, chat is element, etc.
* My part of the world is not adjacent to Germany (where this paid offering is hosted)...so there is a little latency. But not nearly as bad as I expected.
* While file sharing and syncing and other basic stuff is included, the equivalent of online collabora (or whatever the online office suite is called) is not included and you would have to self host it...but hetzner state this in their relevant knowledge base webpages.
My opinion: not as polished as Google Sheets, but good enough. However it's much better than the web version of excel.
Also, your experience will depend on the server your using to run it. Lots of people try to run Nextcloud on very weak hardware to save costs, and it does run well. But office in particular needs a bit more compute and memory to feel fast.
I assure you that it is not. Every organization, public and private, beyond a certain size, has people whose entire day consists of collaboratively editing documents and spreadsheets. Responding to superiors who highlight a sentence and leave comments like "@Team can we tighten this up? Thx".
There is still your random "let's make a list of X on the meeting", that would actually improve if you just had something that collects the items. But out of that, there has been a long time since I last saw people doing it.