The Open Source solution which serves me well for years has been TiddyWiki (1). Supports Tags and various modes of output. Each page one file or all in one, very open so recursive changes can be applied on the shell in plain files.
TiddlyWiki in many ways is the best predecessor to Obsidian, in that it follows many of the same priorities and tradeoffs.
I was a big user of TiddlyWiki but Obsidian has so many UI quality of life improvements, and the plugin ecosystem is evolving at such a rapid pace that I decided to jump ship.
You probably mean the NodeJS version. I agree. It’s not just starting a Docker container. There are more steps involved. And there is no authentication.
(1) https://tiddlywiki.com/