> Why don't all people make their own food?

I do not think that this is a valid comparison.

It would be more like, why don't farmers produce their own food (and rely on packaged food instead).

Most farmers don't produce most of their own food.

The modern world is built on specialization: most farmers have specialized in some direction or another, and the ones who haven't usually make less money. At best, a farmer with livestock will occasionally take a pig or cow off to be butchered (since butchering is another specialty entirely, needing specialized equipment to do well), or a farmer growing corn will plant a few rows of sweet corn in a field near his house, or a farmer growing produce -- usually just a half dozen varieties -- will keep back a little for himself.

But the calories a farmer will produce for himself are generally a small part of his intake. In the end, it's a better use of his time to focus on producing as much of a handful of crops as possible and buy what he needs from a grocery like the rest of us.

Hansons and Jones Soda man, they are so much better.