Perhaps I do have some confirmation bias, but when you read interviews/books about the very best in this game, it appears that a large proportion of them operate from a framework of stunning simplicity. They don't talk a lot about edge either. They talk about principles and the need to align oneself with these principles.
I think: Those profound principles, the correct interpretations of these subtle principles, and the associated know-hows for aligning oneself with them are All 'hard-to-find' Edges, aren't they? lol
