[andrewflnr]

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 haven't heard of or seriously evaluated a scythe.

[jiggawatts]

There's illustrations inside the pyramids that are thousands of years old showing people watering their fields using a bucket on a long swinging arm. It needs just a couple of long poles, a bucket, and a rope.

I saw this still in use today when I went to Egypt. That blew my mind.

https://en.wikipedia.org/wiki/Shadoof