One way to explain the apparent contradiction is that free markets aren’t the same as anarchy. Businesses should be free to compete, but that doesn’t mean they should be free to do anything they believe makes them more competitive. Free market supporters believe they are more efficient than alternatives, but there may be principles of more importance than efficiency.

Plus, certain behaviours are in the interests of specific businesses but damaging to free competition as a whole: monopolies, censorship, etc.