The "invisible hand of the free market" works only, if you have many market participants competing one against another. When a participant wins the competition you get monopoly, when multiple participants collude you get oligopoly, or cartel. Market can not solve this.
Historical examples:
https://en.wikipedia.org/wiki/Standard_Oil
https://en.wikipedia.org/wiki/Phoebus_cartel
https://en.wikipedia.org/wiki/DRAM_price_fixing_scandal
https://en.wikipedia.org/wiki/High-Tech_Employee_Antitrust_L...
https://en.wikipedia.org/wiki/OPEC