A lot of any real gain will be due to novelty, and that will wane once you've been doing it a short time (or once other people in your field are doing it so you all go back to looking the same).

I suspect a lot of the gain isn't even that useful to the channel: it being people clicking to complain. You might not see that mean actual complaints because many will see the existing ones and either just upvote them or move on without doing anything (their chance to repeat their regular comment to get a few upvotes having been taken by someone already having said it).

So you’re saying it boosts engagement, advancing the creators primary goal of putting something on YouTube to begin with?