@zensaiyuki

Yes there very well may be a next-level superior form of communication. the claim here isnt that such form exists, only that we know enough about physics to know that any such form of communication is far far beyond our current level of technology.

So regardless even if species existed that advanced far enough to utilize such a form of communication they would have had to have spend a very long time in the part of their evolution where they were using EM waves first. Which would mean if the universe is filled with intelligent life there would still be a large amount of EM chatter to detect.

@2ck