Now, if I'm watching Anime and YT recommends Shapiro, I can agree that's closer to indoctrination. However, if it only happens like 2 times for every 10M watches of anime, and then 1 time for every 10M it's recommending Young Turks, then it's not really a significant force in this area; and it is only pushing slightly to the right - and I believe this is the sort of thing that the study found. So coming back to your first quote:
> So the indoctrination isn’t obvious? So it’s subtle? That makes it more pernicious, in my eyes.
No, that is not what the study found. It found that political recommendations for right-leaning content are slightly more common than those for left-leaning content.