Sure, but I'd guess that there's a difference if resources are transferred back and forth within a small region, i.e. neighboring countries warring for a few hundred years, compared to some other country far away taking the resources with them after a successful invasion. And then continue to take everything they can get their hands on for the next few hundred years... It pools the resources in a single place, and as a result it also pools the ability to refine those resources in the same place (because its pretty hard to learn refining if you don't have anything to refine). Maybe it could be compared to how a town supported by resource producing villages made it possible to specialize in a trade that wasn't viable in a village setting.

And the killing off part was mostly a reference to diseases brought (without intention) to the Americas that more or less killed the civilizations there.

But maybe I'm just brainwashed by the people on the left.