There is a harder second-order question of “what sorts of videos maximize watch time, and will those be bad for my child?” Hastings’s evidence points toward “yes”, but I don’t think the answer is obvious a priori. (The things YouTube thinks I want to watch are almost all good or neutral for me; YMMV.)
I think it’s well known that it’s optimizing for watch time.
There is a harder second-order question of “what sorts of videos maximize watch time, and will those be bad for my child?” Hastings’s evidence points toward “yes”, but I don’t think the answer is obvious a priori. (The things YouTube thinks I want to watch are almost all good or neutral for me; YMMV.)