This isn't always true. The free market with infinite competition might settle on optimal solutions eventually, but there's almost always a gradient that appear

This isn't always true. The free market with infinite competition might settle on optimal solutions eventually, but there's almost always a gradient that appears due to time. It takes time for changes to propagate through a system and that can be taken advantage of. There's the quote by Keynes that underlines this: "The market can stay irrational longer than you can stay solvent."