Not interested button is a placeabo type button, completely useless, isn’t it? Do you know how many hundreds of times I’ve not interested late night talk show hosts with no stop to their constant recommendation in my feed.
If you actually don't want then then don't click them in the first place and in about a month they will stop showing up.
Don't click the dislike button, rather don't watch the video at all. (Dislike means this video is bad not this topic is bad.)
The videos on my homepage exactly match the videos I watch. Exactly. They are often boring since I want something new - but I can't complain that YouTube is messing with me in some way. (Same with Google News - sometimes I want something new, and it's not there - it's always the same type of stuff.)
People who have videos that displease them on the homepage are watching those videos, and then complaining. "Guilty pleasures" basically.