I’ve noticed this behavior for all Google properties. Every time I click “not interested” “don’t show me this again” or anything similar, it seems to have no effect as the best case. The worst case I’ve seen is when clicking these options seems to acts as a positive signal to show me more of that content. I’ve noticed this over years.

As such, I’ve simply stopped interacting with googles recommendation systems and most of googles content delivery systems. Including using YouTube as minimally as possible.

I feel like they don't use those signals, just time spent...and you spend more time fishing for the 'not interested' button

It's the same in tiktok: there's literally a button that says “I'm not interested in any live videos”, but it keeps inserting livestreams into the feed anyway.