the fact that I'm into a lot of the topics that you've listed but have never heard of these creators simply underscores the sheer scale of youtube

Me too. Youtube must know better than me what to recommend me out of all the videos... still, I get presented the same shite again and again.

To be fair: not everything is shite and Youtube is my favorite social media (especially for discovering new music), but I noticed a big drop in quality from one day to the other a couple of years ago.