I've had this, I take a couple extra seconds to specifically say don't recommend me anything from this channel, and then my suggestions get bombarded with that style from videos from different channels

The most blatant was a specific "Get robux" video that appeared constantly on my feed from dozens of different channels but that triggered this extra engagement in the form of blocking, reporting and disliing

I assume that's exactly it, why else would companies do this sort of thing, or are all media companies inept.

The AI found me and downvoted. If I never post again you know what happened!

I’m pretty sure it’s exactly this, just time spent on page no matter what you’re doing even if it is scrolling past dozens of recommended videos trying to find something half decent.