Let me tell you my experience:
I discovered the dark web about 12 years ago. I was fascinated at first because I believed it hid much occult/esoteric knowledge and secrets that people wouldn't post on the clearweb.
So I got into a few directories and dark web search engines searching for occult knowledge. I was looking for books, sites, forums, any of that sort. I first found a couple of online libraries full of esoteric ebooks, but all of those books could be found on clearnet. Not one of those books was new or exclusive.
Then I found a couple of sites and forums. Again, just mainstream stuff, nothing secret that you couldn't find on clearnet.
Then I came upon a forum dedicated to the discussion of esoteric knowledge. Its first rule was "don't post about black magick". I clicked on one of the posts and it was by a guy complaining. He was saying something like "No black magick??? Seriously??? I was told the dark web is full of advanced black magickians. Where can I find those?". Nobody answered him. Apparently he was someone just like me, and he was disappointed.
So basically it was a waste of time. I searched for about a week. There were all sorts of illegal stuff, but I didn't find any secret knowledge or any people who had it. Only Wiccans and other mainstream occultists who didn't even practice black magick.