if there is anything you started to watch, but didn't like, clean that stuff from your watch history.
click the "Like" button on any videos you like a lot, and favorite the very best.
sometimes YouTube's skull is very thick, but it will get a bead on you fairly soon if you do what you can to tell it what you like and don't like. that's been my experience, anyway.
I tried to turn it on for a while and it didn’t make any difference. Same for likes/dislikes. The only effective methods are channel-wise, i.e. “subscribe” and “don’t recommend channel”, but then the feed becomes 90% of videos I have watched or new videos (from these channels) in which I mostly have no interest in. Other 10% are irrelevant to me.
Anyway, I’ll try to follow your advice (thanks!) with more active liking etc for a while, but my hopes are weak atm.
For example I watched and subscribed to PBS ST to kick start. It instantly flooded my feed with low-quality sci-pop with “pro voice actors” voices and stupid sensational topics like “shocking alien planet” or “will our sun explode tomorrow? Emoji emoji emoji”. No astrophysics was recommended yet. Yesterday I searched for and binge-watched about hyena clan relationships, today it recommended me two quran surahs for good sleep, few colorful open-mouth-sensation morons (not sure which topic they were trying to “wow”) and a very badly compiled drama about different snow leopards chasing goats. And that’s while I’m holding my finger on “not interested” trigger for weeks.
What am I doing wrong?