What about SETI's great silence? It's pretty meaningless. Radiation diminishes with the square of distance. It would take an incredibly powerful directed radio

What about SETI's great silence? It's pretty meaningless. Radiation diminishes with the square of distance. It would take an incredibly powerful directed radio signal to be detectable even a few light years away, and it would have to have simple modulation to have any chance of being noticed. Absolutely. It's worth highlight that Fermi is saying something like "why societies we don't understand using technologies we don't know of to communicate to us."