but there are plenty more frequencies available below that and we've a lot to learn about how to make the most of them
I thought the higher 'radio' frequencies were blocked by the atmosphere and were unusable and of course the lower frequencies have insufficient bandwidth to be useful. I'm certainly no expert but I was under the impression we were already using as much EMF spectrum for transmission as was possible.
I suppose the higher frequencies could be used in a vacuum but that won't be easy to maintain for most applications.