It think they mean more like "nothing on the home page looks interesting show different stuff". Sometimes YouTube will decide " I'm only going to recommend these 3 videos to you for the next month" or just misses the mark on the stuff I'm interested in watching
Youtube consistently forgets that I watched a video just a few days ago (no red line on the bottom of the thumbnail), and will suggest it over and over until you manually go to click on the ignore. Even recently they had a “suggest new” button on top near the “interests” buttons that would appear there, but I haven’t seen it for several weeks or maybe longer.
Youtube will also randomly switch a video I’m watching to 480p even though I pay for premium.
Their suggestion algorithm is also pretty bad to me, although maybe it works for some people.