Filter bubble is one thing. It's another thing to filter content so aggressively that over 50% of the site's content stays the same from one day to the next while still showing content you already upvoted.

That's the reason I stopped using it a few weeks ago - it got so bad I had to scroll down multiple pages of collapsed answers in order to find a single question/answer that I hadn't seen yet. Which is exactly the opposite of what should happen.