I call a class of video video essays, and I think the term has value. Those videos have the form of an essay, they follow an essay structure. Lindsay Ellis makes video essays

That’s different to a video lecture, which is a much more common type. A video lecture tries to teach you something. Lindybeige, and Astrographics and many others do lectures

Then there are a dozen other genres. I think it’s the lectures that get long.