A thousand years ago, it may have been more dangerous to send three times as many villagers to collect water from the river 20km away so that the village would have enough water for everyone to wash their hands, than to have people not wash their hands before eating. The benefits of a practice/tradition can vary over time.
Lots of people may have died from avoidable diseases, but lots of people may also have avoided death by bandits, wild animals, and starvation. (due to more workers allocated to water collection than food production; the extra food produced may have been the difference between life and death during famines for some people.)
Lots of people may have died from avoidable diseases, but lots of people may also have avoided death by bandits, wild animals, and starvation. (due to more workers allocated to water collection than food production; the extra food produced may have been the difference between life and death during famines for some people.)