[mellavora]

Well, for one, I depend on the economy for my food. I also depend on it for my drinking water. Oh, and in winter, for my heat.

Leaving that aside, I've also found the economy helpful in providing me with clothes and shelter.

And when I have gone off in the woods and played survivalist (and yes, I have), I depended on the economy not only for much of the gear which enabled this, but also for keeping me safe from attack by other tribes while off in the woods. No-one was fighting me for a particular foraging/hunting ground.