A free market just works this way, and various regulations exist to keep it a free market by stopping things like collusion, corruption, fraud and monopolies. However, in order to protect creators rights, other regulations we call copyright grant monopolies. So the 'free market' is not really a free market. An actual free market per your economics text book is a rare thing.
That's the pitch that's generally given by advocates of the free market to justify their position. They tend to do so because "the free market" isn't something that is near universally viewed as an inherent good, so it's necessary to convince people that it's existence results in other goods.