I started using an extension that blocks all recommendations. I have my subscriptions and I have the search. Of course, I'm missing out on all that new and undiscovered content... but what I get instead is life, so I think it's a fair trade.
It's weird how different my experience is, simply from spanking the algorithm every time it shows me something clickbaity that I haven't already seen.
I actively use the 'not interested' every time the recommendation algorithm tries to show me something where I don't already know what it is. I pretty much only want to see recommended videos I've already watched :)
It takes some patience to get this going, but it seems to work. Any time I see anything novel, it will get excited for a while until I settle it down and tell it I hate all its ideas. Usually I don't have to tell it never to show channels, though if it's obvious enough I will. Eventually it's back to old faves again :)
I resonate with the "a bit too good", so much so that I exclusively use YouTube in incognito mode because the recommendation algorithm is too addictive, and the content that it causes me to consume doesn't really do anything but waste my time in the long run.
I also second the "horrors that lie beyond", the stuff that regularly surfaces on the default YouTube home page would suffice as an excuse for aliens to blow up our planet and put a freeway through it.