That's still pretty hit or miss for me. I've watched a video about cats exactly once a few weeks ago when my cat did something strange, and my recommendations are still littered with click-bait videos about certain cat behaviors. I watch tons of the aforementioned hour long analysis videos and I still need to resort to playlists compiling them instead of getting recommendations. To me, it seems the algorithm really wants to push certain types of content and will flood me with them if I so much as hover a video too long. But it really dislikes other types of content and almost hides them on purpose, despite me liking them. My best guess would be that longer videos have less ads per minute of content and are therefore not recommended as much, but I couldn't tell, I started blocking ads on Youtube when they added a second ad banner back in the day - long before video ads were a thing.