Tyson Foods, Cargill, JBS, and National Beef controls roughly 85% of the U.S. beef market
CVS Caremark, Express Scripts, and OptumRx manage over 80% of all prescriptions in the U.S
Amazon buys 50% of all books.
These examples are even more extreme than at least 3 major clouds present in the US buying hardware.
The parent comment specified a company that has never turned a profit cornering the entire market.