Earlier quoted context omitted.
This doesn't help when searching. I'm looking for specific things as often as I'm clicking on recommendations. What's needed is a global "Hide AI Dreck". Particularly the overwhelming hoard of AI slide-shows masquerading as reviews.
It's clear that YouTube doesn't want you to have much influence over your feed. You can't even ban specific channels from being shown to you, which would be the simplest thing to implement, and other knobs that previously existed were silently removed. Since Google does nothing that isn't based on metrics, we can deduce that they have data to show that giving people settings to focus the recommendations on what they…
Yes, you can. Click the video's 3-dot menu > Don't recommend channel. Though I have noticed that this only blocks them from showing up in the feed, not in the recommendations sidebar. I also have to run uBlock to hide shorts, already-watched videos, subscriber-only stuff...ain't saying the YT experience is good, not by any stretch of the imagination.