That is not true (or true in only a very restricted sense that barely ever applies). Positive-sum games do actually exist. See: literally everything around you

That is not true (or true in only a very restricted sense that barely ever applies). Positive-sum games do actually exist. See: literally everything around you that wasn't around before people decided to make stuff. Even if we're talking about literal dollars, the Fed can and does print new dollars more or less out of thin air. And this is a really good thing, because we wouldn't be doing very well if we were restricted to the 1792 supply of US dollars.