But the point of Fermi's Paradox is that we are not seeing evidence of alien intelligence anywhere. We don't expect it here on earth, but we look out in space and see no light/radio/other waves that look like messages; no energy bursts or other anomalies that don't have better explainations (though some have no explaination at all). The Great Filter is simply a hypothesis -- like the Dark Forest -- as to why we don't see evidence of intelligent life in space.

If we went back to caves, we'd have great-filtered ourselves.