OK, I didn't know that, though it's not very intuitive. Thanks!

Now, as a parent, I face a tough choice: I have history on the kids accounts precisely because I want to check on it and discuss with them what's good, or less so, to watch.

I've had my history turned off for years, and still get Shorts.

unfortunately turning off history kills all forms of suggestions, including ones like "you're subscribed to these things, so perhaps you might also be interested in...", which is the form of recommendation I want the most since it's driven by what I chose to be watching rather than what I've previously watched.

I had assumed the behavior was malicious compliance on Google's part against California law that said no history had to actually mean no history.

I have had history turned off for years. It won't recommend anything on the main feed, but when I watch a video, it recommends more as usual. There's plausible deniability that the recommendations are based on just what I'm watching but in practice that's obviously not true, many recommendations are based on either my subscriptions or my watch history, as they are not related to the video I am watching but are related to my interests.

Since there's not supposed to be any history, I have to trust it's just based on subscriptions. It seems like that could be the case, I guess? But I do have doubts that they do in fact have my history somewhere that's accessible to this recommendation engine.