It could well be that the exponential advancement in technology makes it so there is only about a 100 or 200 year gap where civilizations send out radio waves,

It could well be that the exponential advancement in technology makes it so there is only about a 100 or 200 year gap where civilizations send out radio waves, or whatever our current technology is capable of receiving - before hitting these other dimensions. But even so, there would still be a chance to detect this kind of stuff. I mean, I totally see your point - I just don't think we're that special though.