This question pertains to One Piece.
I know that Skypians, Birkans, and Shandorians came from the moon. But they should've been technologically advanced right? But Shandorians like Calgara seem to be a small tribe with zero knowledge of poneglyphs etc. Also, they seem to believe in rituals/superstition etc even though they were once an advanced civilization that lived on the moon. Also, they seem way too backward in terms of science and technology. How did that happen?
Also if that's true, then are Poneglyphs a way to find out the story about earth or moon?