I'm never logged in on YouTube, run a browser with pretty high privacy settings, and YouTube's front page is consistently filled with things related to what I've been watching recently. It doesn't seem to keep track over long periods of time, but it'll usually recommend additional videos from the channels I've been watching in the past month or so and other videos with keywords like the ones I've been watching lately. (As well as the garbage-lines of recommended Shorts and other such lines of "specific kinds of stuff that you don't currently watch but we think you should" such as news/politics related things or promoted stuff from YouTube Live.)

It takes about 8 "regular" rows before I hit things that don't seem to make sense based on things I've watched previously, and even then I can kind of see why they might think they're related to topics I actually like even though they're wrong.

Unfortunately, I almost never have actual new things I want to watch show up, because I'm pretty picky about which specific channels within each topic area I want to watch things from, so it's mostly a mix of stuff I've already watched from the channels I like and stuff from channels that I'm not interested in watching videos from even if they are on the same topics. I suppose I should seed some new topics again to get my recommendations less same-y.