It seems like the algorithm panics, because you don't engange with anything much, or because your interests shifts to often and it can't deal with it. So it falls back to boobs.
There's also a sad trend of assuming that because you're into lifting, your also misogynistic. The more you engange with fitness content, even if it's training programs or how to correctly do certain exercises, platforms like YouTube will start flinging misogynistic content at you and it's incredibly hard to remove.
In my experience, it has worked (my discover page is an amalgamation of classic Simpsons, Dropout.tv, and Whose Line Is It Anyway?, while my Reels feed is unhinged in the right way.) But also I’ve stopped using it because my brain was melting.
That explains why out of no where I got reccomendations for some gender conflict greentext channel, I had just that week been looking for lifting techniques.
It is fairly concerning and there's not real good way of telling YouTube that you're not interested. The dislike button does little and blocking the channel is also pretty ineffective as there are a myriad of channels with the similar content which you'll just be served instead.
Anyway, I know exactly what you mean. I have certainly seen YouTube pigeonhole me into a demographic that I'm not even remotely part of. One day I watched some ham radio-related content and then a couple of rugged flashlight reviews and YT decided I was a tacticool doomsday prepper would NOT stop suggesting videos about conspiracy theorist podcasts and how to make guns at home.