That is the peisely point: "millions billions of individuals cooperating for the optimum outcome in pursuit of the Nash equilibrium" is just a longer name for the world's economy, including all the corporations, governments, regulations, criminals, etc., each one with its oun idea of what is the "optimum outcome"; and that is just too complicated a system to predict its future evolution with any confidence.  Including whether those billions will adopt bitcoin, or some other cryptocoin, or will stick to credit cards.