Most markets inherently turn non-free when left unsupervised. That's the insight that folks like Keynes came to (as does any honest, informed observer with two or more functioning brain cells). That's why anti-trust and competition-preserving regulators and laws are essential. Without them, a very few powerful players form [0] cartels and/or tri/du/monopolies and enrich themselves vastly out of proportion with the value that they provide to their customers.
[0] ...often legally protected...