I prune my watch history regularly, but something really changed late last year. The algorithm became like "oh, you've watched a single video about X, how about I show you these 89 other videos about X for the next week or so".
Most recently I watched a highlight video of Australia vs West Indies test cricket series my home page was endless cricket videos.
A few weeks before that I watched highlights from World Cup Asian qualifiers, for a week or so endless soccer videos.
My watch history is basically entirely my hobbies and interests and thus YouTube suggests more stuff related to those. A lot of it is channels I'm already subscribed to, but it does a good job of surfacing new channels that I wouldn't otherwise know about it.
Just because I look up one video of “how to replace a toilet seat” doesn’t mean I am a connoisseur of toilets.
The other problem I run into is that no matter what I’m watching, I’m two autoplay videos away from Joe Rogan (and other right wing personas). Who knew something as innocent as listening about the economy of Iceland can be two videos away from why the Superman movie is too woke.
My YouTube ads (and Recaptcha experiences) have gotten terrible because Google seems to punish you more the less data you feed them, but for the most part I feel like I have control of the data that I do feed them (some of which is intentionally misleading because they have no right to know and I hate targeted ads; I love Spanish language ads, for instance, though my level of Spanish comprehension is stuck somewhere around first year of high school courses).