Not trying to be a downer, but I've worked the trenches of an internal IT help desk for a company, and you should prepare yourself for doing free volunteer tech support if you set something up like this. You'd be shocked at what things can be road blocks to otherwise intelligent, seemingly technical people. The risk of it drops if you use something more standard like Google Sheets, but it doesn't disappear entirely.

You will probably need to go with something that works for the lowest common denominator of your group. That might be "horrible messy email thread manually turned into a shared Apple or Google calendar once a week by a volunteer". If you don't, there will be constant friction with them. I've seen similar collaboration efforts fail on a team of professional systems engineers simply due to a difference in how each person wanted to take and maintain their notes. No one could settle on a standard and eventually the person pushing for it gave up.

In short there are multiple angles to this, more than simply privacy vs ease of use.

That said, nextcloud appears to be the current standard for this outside of Google and Microsoft.

Aside from self hosting something like NextCloud, you could also check out Cryptpad.fr

Yeah you can use a self hosted nextcloud or similar, or maybe you want a wiki rather than a spreadsheet.

Cryptpad

nextcloud

track different things, tasks, and who’s doing what and when. Think of inventory, shifts, etc

I agree that Nextcloud with Collabora might be your way to go here, but this line made me think: maybe kanban board would be more what you need? I use Nextcloud's Deck for that, but even the devs say it's not production ready and it is true. It gets slow with more cards

Other software like this. From my notes, not vetted, not checked, just gathered in case I want to migrate out of Deck. Should be mostly open-sourcish

• https://vikunja.io/
• https://github.com/plankanban/planka
• https://www.openproject.org/?acuuid=e13029ec-0feb-413b-acce-25d49be4d880
• https://taiga.io/
• https://kanboard.org/
• https://github.com/wekan/wekan
• https://www.techrepublic.com/article/open-source-kanban-boards/

Of course, NC provides a lot more, you could even have your own Meet (Nextcloud Talk), so maybe it's a good idea to have it anyway

Also, there is OpenCloud. IIRC correctly there is some history between NC and OC but I don't remember the details

EDIT: since you initially started with searching for a service, there are offers where you maintain the NC but the most technical part is done by a company. I remember Elest and Hetzner but probably there are more

Pen and paper is probably the right choice here.

Read the room and make sure others are onboard. Make yourself too much of a dug in wingnut and you'll undermine your actual work

Baserow or NocoDB?