This. I mean thats just one sector, but its spread across the whole: the whole of modern economic theory is one of competition that causes efficient markets. But when you look into the theory even a little bit, you realise it needs hundreds, even thousands of market players to reach an equilibrium thats worthwhile, and the existence of a large player even at like 10% market size can distort everything beyond usefulness. We're so far removed from that ideal in pretty much every dang sector that anyone preaching or believing in efficient markets is just foolish.