Contrast the life of the Hill People with the lives of those who had lived in the Place of the Gods in "By the Waters of Babylon."
The Hill People are extremely primitive when compared to the people who lived in the Place of the Gods. They have lost almost all of the knowledge that those people had.
We know that the people who lived in the Place of the Gods were what we might call "modern people" with cars and electric lights and running water and some sort of weaponry that could essentially destroy civilization. By contrast, the Hill People are very primitive. They live by hunting. They have fires for warmth and cooking. They have to rely on the "dead places" as a way of getting metal and they are so superstitious that they fear the metal. They are proud because they can still spin wool on spinning wheels and their priests are literate and know "secrets" like how to stop bleeding.
Clearly, the Hill People live very primitive lives compared with the people who had lived in the Place of the Gods.