> regions where sickles (or machetes) are traditionally used I don't understand how it's possible that there are regions that don't use scythes (for crops that warrant them), when scythes have been around for over a thousand years? I would venture to say that if they haven't transitioned yet it's because they don't want to (for whatever reasons--no idea what those might be).
Invention and adoption of technology, even "basic" technology, is very contingent on circumstance. Bows are pretty near universal (but not quite), but specific improvements like recurved limbs are patchy. And people aren't exactly quick to adopt new farming techniques when a failure could mean they starve. I guess that's also why this organization is pushing uphill. But I think it's very possible that lots of people…
I saw this still in use today when I went to Egypt. That blew my mind.