OBSIDIAN FOR THE WIN!

If you have *lots* of info you want to organize, AND you have time/energy and DIY spirit to incrementally configure and combine plugins etc.

Then you can't beat Obsidian.

I also rejected it out of hand, until someone mentioned that is CAN do text-folding (which is critical for me). This was not apparent when I first used it, so I left.

Indeed most of the commands are not even bound to keys, so as you learn which commands you regularly use, you can bind them to keys. It is very DIY, and not very documented. Still if you want your tool to fit the shape of your knowledge, nothing can shape shift like Obsidian. (well there are a couple of contenders, LogSeq and Roam) but obsidian beats those, at least for me!