Going to go big here:
Trade has intrinsic worth. If both parties benefit from the trade, or both perceive themselves to have benefitted, trade’s purpose has been accomplished. It’s not about the things that are exchanged, but the people doing the exchanging. People enjoy trading.
Trading is fun. It makes you feel good when you make a “good” trade. What I mean by this is a trade in which you know you have benefitted and so has the other person. Or at least you know you didn’t try to rip them off, which I think is an awful feeling that I’d never want. Why is that? I don’t know. I don’t really question it.
Trading ties directly into game theory concepts of cooperating and defecting. And it’s been shown that in game theory when you have multiple interactions with the same party, the best outcome is reached for both parties (or any number of parties in a system) when most people behave well most of the time. Thus trade encourages good, cooperative behavior, which leads to all kinds of good results. Like the prevention of war. Or limiting war.
If the thought experiment you run were true, it wouldn’t just be true that we wouldn’t need trade. We wouldn’t have any need for each other. If everyone were identical and had the same skills and the same needs, what would there be to talk about? What to do? How would we organize? We’d be Ricks in the Council world, wondering why the hell we’re the Rick who has to stand in the assembly line instead of “Cool Rick”.
Trade helps us find a place in society. Because we all have different gifts, we can all contribute in novel ways, and feel that emotion of contribution. Without that feeling, we go towards dysphoria, towards feeling that things aren’t real, or ought not be real.
So trade is “for” getting people to organize into societies of cooperating individuals each doing things that they are suited for so that they don’t have to do the things they aren’t suited for. So that they feel better, and want to keep building the society rather than rejecting society (dysphoria) and splintering off to make their own tribe.
Exactly. Trade increases cooperation, which adds tremendous value to human life.