> observing highly successful people after they are already successful is not terribly useful

Plus, successful people themselves start looking for the "why" only after the fact - and most often don't realize to what degree most of it was about being at the right place at the right time, not really about their "super power".

But I get it, this is how you sell books, for whatever they're worth.

In other words:

Ever met someone who wrote a book "These are my super powers that will make me rich in a couple of years - Just watch me"? No, you haven't - because nobody can tell in advance, even if they know exactly all they're strengths.