It's frustrating that nowadays YouTube seems like it can only keep 3 or 4 types of videos that you like in its head. I feel like I'm watching the same thing over and over whenever I click on recommendations. I totally agree with you.
There was a time a couple years ago I watched one episode of Arthur for nostalgia purposes and it completely obliterated my recommendations. I scrolled for hundreds of videos and didn't see a single non-arthur one. It took months for the site to become usable again.