So far I'm pretty happy with TiddlyWiki - steep learning curve and a bit of a hassle to get setup right, but I can't go a day without it if I'm hacking at something. https://tiddlywiki.com/

Highlights:

* You can drag-and-drop plugins from other wikis you come across

* You can write own plugins and customise everything

* Hostable as a self-contained file (one index.html) and it builds itself (a quine)

* You can host it in Node if you want stand-alone note files

Still didn't figure out a good mobile workflow though.