Hard to catch a disease when it’s always the same 15 people around you, with no communication to the outside world; and no factory farming that incubates most of these diseases.
Regarding your reference to how brutal and never-ending work was; As far as we know, many European medieval farmers had 1500-1800 working hours per year. It’s also a bit gloomy to assume the household was run by two parents and their kids - often, grandparents were colocated and helped until they couldn’t. What you‘ve described was certainly the case during famines and war, but not a permanent state.
Regarding your reference to how brutal and never-ending work was; As far as we know, many European medieval farmers had 1500-1800 working hours per year. It’s also a bit gloomy to assume the household was run by two parents and their kids - often, grandparents were colocated and helped until they couldn’t. What you‘ve described was certainly the case during famines and war, but not a permanent state.