I know you don’t mean China, life expectancies in the villages where they have that kind of hard life is way lower than the cities. That hunched over Ayi still farming when she looks like she is 80 seems amazing, but then you’ll find out she is only 55.

Actually, I don’t think this is true for any of the East Asian countries I’ve visited, it seems to be a romanticized myth of the west.

Can you be more specific? After visiting China and Vietnam and seeing the very difficult and tiring conditions people have to endure as a way of life, I don't think the elderly there can say they're in good shape or physically fit.

Most likely you were only exposed to older people who were still physically fit enough to continue being able to provide for themselves, and never saw the vast majority of people in their 50s and 60s who are permanently physically impaired.