I have come to a conclusion lately that there is no free lunch. You either optimize and increase risks (of system becoming monopoly like rail roads in the past, or busting like mortgage companies in 2007-8, government becoming tyranny, something like that) or you pay for inefficiencies. I think the free market is really about finding a balance between optimizations and risks. If the company is too optimized and carries significant risk - eventually, it will bust. If the marker is not efficient because of transactions volume - a larger company will inevitably emerge (and if it continues to grow - eventually bust)

EDIT: what really worries people about monopolies is that it takes more than a generation to see these companies bust. And to, again, optimize it, we come up with antitrust laws... But any optimization, in my opinion, costs risks and never is free (as in lunch).