I agree with you that power brings blinders (as well as bringing some useful sorts of vision: I've watched more than one person improve their self-understanding, and their understanding of why organizations are structured as they are, once they got in a position of responsibility).

I also agree that people who have something work for them often run around recommending it way too much, with way too little attention to the person in front of them.

That said, when I get advice from people or books, and when I actually try the advice, it often works. Enough so that I should be ditching my current habits and trying out new forms a lot, if I want to actually be effective. I would have thought this would obtain for most people (and that most of us stay consistent in our habits for much the same reason that we stay consistent in our initial disagreements with epistemic peers -- inertia, fear of a status hit from changing, that sort of thing). But maybe people vary here?