@mk The original post is about wealth not being a 0-sum game. No matter how much some have that does not imply others had to have less for them to have more.
To put that in simple language. If the whole world had only two people, and one had X wealth, the other Y wealth, it is possible (and in fact fairly common ) that both values can increase over time. In otherwords, everyone can get more wealth without anyone loosing wealth. Over time that has overwhelmingly been the case as is evident by the fact that we arent still living in caves.