Anti-competitive legislation doesn't just apply to pure monopolies. For example see the investigation into tech companies agreeing not to steal employees of eac

Anti-competitive legislation doesn't just apply to pure monopolies. For example see the investigation into tech companies agreeing not to steal employees of each other, just because there are other companies out there that hire developers it doesn't mean such practices can't violate antitrust laws. A more relavent example. Consider that you lived in a city where some service was provided my only a single provider (for example a bus service or cable internet service), even though you could move to another city to use alternative services, those operators are still considered to have a monopoly because moving houses is a high barrier to switching. Similarly switching phones is a high barrier due to contracts and other purchases (apps, books, etc) causing you to be tied in. In the NBC example, switching between stations has negligible cost. Many pieces of legislation have been introduced for the sole purpose of reducing switching cost (for example reverse engineering for compatibility legislation), because high switching cost can create localized monopolies.