Of course market inefficiencies exist, but their impact is much smaller than what critics of capitalism like to imply. Amazon and fishing operate in a market with plenty of competition. My point is that the value that a fish futures owner holds is real.
> This doesn't happen though
This happens all the time.
The point isn't that it's literally impossible to compete, the point is that there's a large barrier to competition that provides no value to anyone other than the entity that created it. Time and money was spent to intentionally make the market less inefficient, so that the newly inefficient market could be exploited thereafter.
Yes, a new entity could then decide to invest time and money to try to jump over the new hurdle, or toward tearing the hurdle down. But all those man-hours and all that money spent on lawyers could've been put toward something else that creates actual value to a wider slice of society.