Honestly, the closest I have found is github.com/baggachipz/tinylist It looks like keep, can share and edit files with other people, which is something a lot of things are lacking and I use it extensively for that. Also, I don’t like the recommendations of using MD apps/files for a simple checklist/random notes app. That’s way too much for something this simple and I use Obsidian as well. But they serve much different purposes.
It allows you to host your own database for it, and there is a guide on it.