My experience is different. My recommendations are all math and cs related. It is based in your watch history and you can remove things from your history and recommendations will change. If you haven’t watched many videos in your account then just find the type of videos you are interested in and prone the recommendations.
It's only partially based on history these days. The YouTube subreddit is ram packed with posts about the issue, it looks like 50% of your recommendations are relevent to you, the other half is randomly generated with seemingly nothing in place to at least try and match them up to your known interests.
It started approx 2 years ago and has gradually gotten worse to the point where some users see no recommendations relevent to them at all.
