Easements and the monopoly they sanction are the reasons that everyone in an area can get service at all. If they had to write a private contract that would cover the absurdly high cost of laying cable, it would make a cell phone contract look like a love note. It would have to be a covenant imposed on every tenant of the building for many years. It would be just like regulation, only written by people with an immediate incentive to do it as abusively as possible.

Real-world markets lack infinite competition and perfect transparency, so they pretty routinely fail to deliver optimal solutions. Many famously wealthy people got there by exploiting strategies to make markets fail.