You're comparing what even our ancestors before sapiens had against the modern world. How about Babylon? Or the native Americans that so many "civilized" Americans ran off into the woods to join. Survival of the fittest was absolutely a thing sure, but at the same time, look at people's lives now, look at healthy people's lives in Brazil's favella, Gaza, Sudan, war zone or not. I live in the wonderful capital of Scotland yet there are people on the edges who have lives worse than a 3000bc person.