Processed foods started becoming a major thing in the 1950s, when memories of the Depression and the Dust Bowl still loomed large in the minds of American citizens. Processed foods are designed to keep for longer, ship over long distances, and be manufactured in bulk, allowing for people in famine-affected regions to still be able to purchase food from elsewhere affordably.

It's fine to restrict yourself to a diet consisting only of locally grown, organic, whole foods, and to never eat meat from a chicken whose résumé you can't review first. Just be aware that you are making your food security dependent on the conditions of your region.