Aliens confirmed retarded, the world is both becoming more prosperous than ever with a lack of mortal enemies and an enemy can easily be conjured up if necessarily, look at covid
You are doing a mistake, when there are 2 with different sex, they can do seggs (Adan and Eva), but when there isnt seggs, someone dead (Cain and Abel, or Shinji and Asuka)
I like this twist in the manga, now we understand what the Alien doesnt understand the love or love at Rep in the begin