No, that increases the survival rate, but it's been documented for thousands of years at least that the "natural" human lifespan is over 70. Mean lifespan has

No, that increases the survival rate, but it's been documented for thousands of years at least that the "natural" human lifespan is over 70. Mean lifespan has been dragged down mainly because of high rates of infant mortality and, as you allude to, various untreatable diseases. But as we make progress on those, the mean has been shifting up.