Unfortunately, it is not a rule that can be applied to every economic situation. In particular, utilities, such as electricity, water, and telecoms form natural

Unfortunately, it is not a rule that can be applied to every economic situation. In particular, utilities, such as electricity, water, and telecoms form natural monopolies. One a set of infrastructure is built, the company controlling said infrastructure can put up massive barriers to entry, as they control the physical devices that provide the good or service to the consumers. Even your example of unregulated spectrum would require a significant investment in repeaters and antennae. Once a company or consortium built out that infrastructure, what prevents them from denying that infrastructure to competitors, just as traditional ISPs are doing today?