I'll listen to an anime music playlist and my entire recommended video / front page becomes full of anime stuff. An in-law joins Youtube to watch bible study videos and now they're an avowed freedom fighter against the globalist satanist cabal running the world. That sort of thing.
The problem when it just puts it all in a single recommendation feed is that that feed more-or-less presents itself as "here's what the world is talking about" rather than "here's a bunch of stuff that conforms to the biases and ideological filters of the stuff you've been watching lately." It creates a solipsistic worldview if you're not aware of what's going on.
And speaking of YouTube, the other annoyance is the extremely idiotic anti-feature of pausing the playback and displaying "Are you still watching?" popup after you go a couple of minutes without moving your mouse or tapping on the screen. No YouTube, I'm not watching, I'm only listening on my wireless headset. But you already know that. What you don't know is that I'm in the middle of some household cleaning and my hands are covered with caustic chemicals, so I frikkin do not appreciate having to press a stupid button you introduced to get more "engagement".