Where are the Radio Signals Part 2

Recently I talked about the Fermi Paradox. That is, why aren't we inundated with radio messages from other species in the universe? In that post I mostly talked about the technical reasons we may not be getting radio signals (e.g., we may not have the technology to detect them). 

But I forgot about the practical reasons. For example, we may be the first civilization to invent radio. I find that hard to believe since the universe is 13.8 billion years old. The Milky Way Galaxy is 13.6 billion years old. That no one came before us seems nearly impossible.

The early universe was metal-poor (because metals had yet to form in old stars and supernovae). Maybe we're the first since there was enough metal to build a civilization. Maybe.

The other consideration is maybe civilizations who reach high enough technology are wiped out by nuclear war, pandemics, climate changes, pollution, overpopulation, robot uprisings (AI), nanotechnology or other calamities. This is a rather pessimistic view and I'm always (well, mostly) the optimist. But it could be things out of that civilization's control like a large asteroid strike or a nearby gamma ray burst (and it doesn't need to be that close, like in the Milky Way). Us humans barely have protection from large asteroids and we have no protection from a nearby gamma ray burst. Or the alien civilization might be wiped out by a super volcano like Yellowstone erupting. 

Why do you think we haven't had any radio signals from alien civilizations? Let me know in the comments below.