How free is a monopolized market? If a regulation outlaws monopolies, does it improve or impede the market's freedom? Regulations that improve market efficienc

How free is a monopolized market? If a regulation outlaws monopolies, does it improve or impede the market's freedom? Regulations that improve market efficiency are good. Regulations that impede efficiency are bad. In practice, we do need regulations because real-world actors are not optimal rational agents.