That's because you've been vaccinated and centuries of disease outbreak management have decimated the prevalence of infectious disease. You're also far more lik

That's because you've been vaccinated and centuries of disease outbreak management have decimated the prevalence of infectious disease. You're also far more likely to have medical problems from a hunter-gatherer lifestyle: frequent activity can lead to injury, frequent contact with animal life, and poor food sanitation. Not to mention that once you get sick you can't produce food, which means your tribe has to support you. Which would be okay if food is plentiful and only a few people are sick, but if there's an epidemic suddenly your half your tribe is sick and no one can gather food for the next two weeks.