I'm going to go against the grain here and say my YouTube algorithm is great. Signing out of YouTube and viewing the default home page is a reminder of the horrors that lie beyond, but my little corner of it is a bit too good.
There was a period of time semi-recently when the algorithm was better than my heuristics, too. I had associated too-good thumbnails with overproduced shallow clickbait videos churned out by content mills and "grindset" individuals. But at some point basically everybody started optimizing their titles and thumbnails and some of the stuff the algorithm was suggesting was actually good even though it looked "too flashy."
There was a period of time semi-recently when the algorithm was better than my heuristics, too. I had associated too-good thumbnails with overproduced shallow clickbait videos churned out by content mills and "grindset" individuals. But at some point basically everybody started optimizing their titles and thumbnails and some of the stuff the algorithm was suggesting was actually good even though it looked "too flashy."