The reason is that life is very hard without electricity, gasoline, corporate agriculture, and modern medicine. If you had to compete with the entire human population as well as natural predators, you wouldn't have seen a plethora of game within rifle range. And the way of life you are complaining about is directly responsible for the production of rifles that can accurately and easily harvest animals at longer ranges. The deer and squirrel populations have exploded specifically due to human agriculture.
If you could hop in a time machine and go back to the land before cars and electricity, you would find out really quickly why people endeavored toward the industrial revolution.