The purpose of Yila and her companions on this trip was to awaken the mechanical bodies within the ruins, those ownerless, dust-covered mechanical bodies... or rather the mechanical bodies that Favignano couldn't awaken in the past.
Taking those young beastmen girls home was just a side task.
The so-called "ruins," although widely featured in many novels, animations, and films, don't represent a world where "technological progress relies on archaeology."
Even though comparing the key to activating the mechanical bodies, the Divine Tears and Artificial Divine Tears, to USB drives from ruins made it seem like ancient technology was highly advanced, the truth wasn't like that.
Technology always advanced... whether it was farming tools or systems, they evolved with the times, accompanied by the silence of the gods, as humans and all sentient beings found their own paths.
