I wonder why simple shoes (like a piece of wood and some cord) picked up in the East but not in the West.
Yes, but both that and the style linked in the other comment are more complex than the Japanese style sandals. They are just boards with some holes drilled and knotted cord put through the holes. Some have two other pieces of wood underneath them to raise them off the ground a bit (maybe they work better in mud?).
They look like something you could take an afternoon and make enough new ones for your whole family, if you’ve got some wooden planks and cord.
Clogs look like they’d each take a while to carve and would require more skill to craft.
Though I don’t know how common either of those were among the poorest of each region.
They were picked up in the West as well, but not as well known probably because they weren’t viewed as fashionable. They’re called Pattens FYI
Patten (shoe) - Wikipedia - https://en.m.wikipedia.org/wiki/Patten_(shoe)