This depends on the market, though of course it's not the case that a market would naturally tend to the best kind of competitive environment serving it. For e

This depends on the market, though of course it's not the case that a market would naturally tend to the best kind of competitive environment serving it. For example, there is an argument that markets with one incumbent among several competitors can serve a market better, since the incumbent will have profits through it's economies of scale with which it can reinvest into R&D to serve the market better, that it needs to maintain its incumbency.