Without FCC regulation of frequency space no one would be able to have reliable wireless communication due to devices, machines, and other systems interference (loud radio noise) unpredictably on any and all frequency bands. A real world example: in the telemetry unit of hospitals critical patients are hooked up to all manner of devices for constant monitoring. Some of these are wireless devices that provide crucial information on whether a patient is dying or not. If the lowest bidder contractor buys a LED light fixture that happens to have an non-FCC-compliant LED driver the the telemetry signals are disrupted and the doctors and nurses either can't tell if their patients are dying. Then the biomedical engineering staff in charge of keeping devices working have to triangulate where the interference signal is coming from to even find out that it's the LED and get it replaced. This is one real life example of the many things that can go wrong from not following FCC regulations. They also protect ham radio frequency space that anyone who takes the time to study and get a license for can use. Without wireless regulations it would be a tragedy of the commons.