And by the way, your statement is also extremely ill-defined. If you say that most transactions are not zero-sum, you are presupposing some kind of value system, which you didn't specify, and the value system for which that is true are also very ill-defined.

It's also true that a positive sum interaction could absolutely be exploitative. So the actual amount of exploitative interactions is strictly higher than the number of zero sum or negative sum interactions.

One could say something similar about "betterment" in your original statement.

> Capitalism/free markets do not guarantee that humans are not shitty

Obviously.

> but I challenge you to find a social system that does.

We shouldn't let the perfect be the enemy of the good. It irks me when "capitalism/free markets" is presented as some kind of "best possible economic system," or that it cannot be challenged unless the challenger is perfect. It's a set of trade offs (advocated by people with their own agendas), and I see little reason why different people shouldn't advocate different sets of trade-offs.