What would happen then to usability of the spectrum?
Highly recommend getting a Ham radio.
When the apocalypse happens licenses will likely not be checked
Discussion
It should all be usable. Like drinking water without having a license to do so.
It wouldn’t be if there aren’t enough water places to go around. That’s what I mean about spectrum.
It becomes a power transmitting game. Jammers literally broadcast super high power on a specific frequency to drown out any other transmitters.