I think there are just too many unknowns around topics like the existence of intelligent aliens, etc., to draw any firm conclusions about anything. We don't se

I think there are just too many unknowns around topics like the existence of intelligent aliens, etc., to draw any firm conclusions about anything. We don't seem to see conclusive evidence for aliens. Okay, maybe a few anomalous UFOs, but none of that stuff is anywhere near firm enough to conclude anything as significant as aliens. We have lights in the sky and funny radar blips, and those could have many explanations. That doesn't mean there aren't any aliens. It just means if they're around they are not advertising their presence. There are many rational reasons not to do so, some altruistic and some self-interested. An ET studying us might want to avoid contamination just like we do when landing probes on other planets. It might also fear that we'd be hostile, and looking around at how humans behave that would not be an irrational concern. If we did respond with hostility or fear, our ETs might face an awful moral conundrum: risk letting us continue developing to the point where we become a danger to other life (including them), or exterminate us preemptively. Might be best just to not make contact and avoid that situation. 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. That means an intentional transmission, and one of incredible power. I don't remember exactly but to reach stars dozens of light years away I recall seeing numbers in the hundreds of gigawatts of radiated signal power. That would be on the order of the entire output of the USA power grid fed into a transmitter array to send e.g. Fibonacci numbers and say "yes we are here." That's unlikely for many reasons: it's expensive, a literal shot in the dark, and potentially dangerous. You don't want to get an answer in the form of a relativistic velocity impactor in a few thousand years. Incidental radiation is just not going to be detected at any range. It's not powerful enough. Not only that but as we evolve toward more advanced and efficient technology we are abandoning powerful transmitters in favor of low power cellular systems with lots of small transmitters or mesh networks. Our transmissions are becoming quite a bit harder to detect over time. You couldn't detect an 802.11 network from the Moon, let alone another solar system. There are just so many unknowns. Nothing firm can be said. If people want to get apocalyptic when reasoning from the Fermi paradox, it says more about their attitude than the universe.