I'd say Outline, almost fits the bill – individual read tracking is happening in the background but we don't yet surface that to the user – there's an open issue for this and it should get tackled soon, I'd link to GitHub if it wasn't down :)

Zim desktop wiki seems to fit you requirements. It's local and designed for a single user, but if coupled with Syncthing works across devices nicely.

> Any wikis do that? Track individual reading? and which ones have the best non-techie UX where I can easily add images, diagrams, video, without having to jump through hoops?

OneNote - while not a real wiki in my opinion - was close enough and could do this and I sometimes recommended it to Microsoft centric clients of mine.

Now they are leaving the version I liked behind but some people might enjoy the new version.

I wish One Note allowed markdown blocks, I like how easy you can paste things like pictures and drawings, but it does not work well for stuff like code blocks.

Off the top of my mind tagging is also a weak spot (it insists on users using one of a number of defined tags, and while tags can be added it takes time and you also cannot type them out but have to rely on clumsy nested dropdows for all but the top 10 that can be reached via keyboard shortcuts.)

I'm fairly certain there was more problems but all in all OneNote still used to be a good solutions for smaller companies that was stuck in Microsoft land anyway.

Drupal had "books" out of the box, that checks the tree view structure. Not sure about the tracking but it seems it wouldn't be difficult to set up. Disclaimer: it's been a decade since the last time I installed Drupal.

Oh, and "books" were a kind of wiki, in case it wasn't clear.