Preserving food by drying it is prehistoric. Humans have dried food for millenia, and it works as well now as it did way back when. In this sense, I am not talking about grains and seeds that naturally dry on the plant, with no interaction from humans, but rather foods that need a bit of help to dry without going bad.
Let us take, for example, apples. Dried apples are wonderful, but leave that apple of the tree and it falls to the ground, and just rots. Apples are too moist in their prime state to dry whole, especially if nature is all that is working for one.
Enter mankind to make a better process. We have learnt to peel and slice the apples, and then put them into a place where the water is lost rather quickly, before bacteria and molds can grow. Please read further.