This is a fantastic project. Thank you for your effort!
From the comments here, I see one of the ways to improve it: currently, new projects are supposed to be added by their authors. Please consider allowing more community input on the next iteration: the ability to add projects, propose changes, etc.
The greatness of FOSS lies in its community.
I myself can recommend Outline[1] as an excellent self-hosted alternative to Notion and BaseRow as an alternative to AirTable.