As we've seen and has been pointed out in the shows, humans are as violent as the klingons, logical as the vulcans, paranoid as the romulans, greedy as the ferengi, cunning as the cardassians, relentless as the borg, stupid as the kazon, empathetic as the betazoids, adaptable as the founders, and so on in various measures as various situations require.
Now from a writing perspective, it makes a ton of sense that the various alien species all represent a highlighted and magnified aspect of humanity in much the way the olympians did to the ancient greeks, but from an in-universe perspective what can explain why humanity is the way it is, how it went from nuclear annihilation to being one of the most powerful and influential species in the galaxy in ~300 years?
Now from a writing perspective, it makes a ton of sense that the various alien species all represent a highlighted and magnified aspect of humanity in much the way the olympians did to the ancient greeks, but from an in-universe perspective what can explain why humanity is the way it is, how it went from nuclear annihilation to being one of the most powerful and influential species in the galaxy in ~300 years?