It is hard to decipher exactly what the goal is for the economy, but I’ve always believe it is there to keep order, to give some kind of rhyme and reason to life, to somewhat simplify everything, because face it, a farmer won’t have time to go n build a car in time, make all the furniture, but other people can, and instead of simply trading goods, but using a middle holder, something simpler than carrying a bundle of apples or chickens with you everywhere in case you need something for emergencies. It is a valid system, but take note it is far from perfect.