I've self-hosted for over two decades and most of the apps you mentioned I've not heard of or used. I self host email and my web apps and system services I wrote. I do it because I like it.

Dewey decimal system IIRC from my school librarian days in the 70's. I'd search like this:

https://github.com/topics/dewey-decimal

This might be a start:

https://github.com/SardineDude1