I kinda feel like we would have done way, way worse without commerce. We're social beings. We do better when cooperating than trying to go at it alone. Commerce is merely one of the many glues that keep us cooperating on some level. Yes, it also leads to competition; but less so than it would without it. Why kill you and take what you have that I want when I can just give you something I have that you want for it?

Capitalism, and making commerce the end all be all of civilization is what we could do without. It's a means to an end, not the goal.