For instance, I can’t download completely youtube pages with videos using wget, but can with pywb (though pywb has issues with sites like reddit).

Not that I would necessarily use it for youtube pages, but that’s an example of a complex page with lots of AJAX.

Doesn’t work well for more complex sites.

… at least 8 years late

It was like watching a scene from an episode of a reality TV show from the early 2000s.

That’s not a coincidence.