I believe the answer lies somewhere in the middle. Economic output is not entirely static, but it is not completely accurate to say a creative hard-working person who comes along and amasses a lot of wealth has created all of that wealth either.
This should not be a controversial statement. Imagine a simple scenario where Walmart alone, represents the economy and they sell 100 units per year. Then Amazon comes along and starts competing and after a while Walmart is only selling 50 units a year and Amazon is selling 60 units per year. You could now argue that 10 units/year of wealth have been created.
Maybe I am misunderstanding you but it seems you are arguing that 60 units/year of wealth were created in this scenario?
Of course this is only a simple scenario where all the variables are fixed, in the real world there are thousands variables (or more) interacting with each other. Which is why IMO, it's overly simplistic to say that one person's prosperity is zero-sum but also equally simplistic to say that wealth is created independently of the rest of the economy.
I don't think that's what's being argued here at all.
The point is primarily one about productivity growth and that causes the economy to grow. Consider agriculture.
When we were all out in the fields plowing them with oxen the whole time, and grinding flour by hand with stones, we didn't have much time to be doing anything else.
The invention of water- and wind-powered mills reduced the amount of time spent milling. Add (in no particular order) the seed drill, the horse-drawn reaper, pesticides, crop rotation, scientific theories of plant breeding, combine harvesters, nitrogen-based fertilizers, insect-resistant bio-engineered crops etc.
Productivity in agriculture in the developed world has DOUBLED since the 1960s.
John Deere invented the self-scouring steel plow and became famous and wealthy as a result. Some of that wealth came as a result of people buying his plow instead of buying someone else's; but the economic growth that resulted from his innovation was in terms of improved efficiency in farming in the plains of the Mid-West.
The creation of wealth extends far beyond the mere sum of natural resources. It's about the knowledge required to make use of it. Finding it, understanding it, combining it. Knowledge expands the range of our reach and of our ability to re-arrange - to create. In my view, wealth creation has its foundation in the expansion of knowledge.
Knowledge does not have the same scarcity properties as physical objects. If there is one harvester, for example, only one farmer can use it. But if there is one new idea for how to harvest crops more efficiently with the harvesters that farmers already have, every farmer that learns of it can use it.
Fossil fuel based energy sources dramatically lowered the cost of food production in terms of how much human effort was dedicated to it. Where the next breakthrough will come from is anyone's guess. That's the nature of capitalism. There isn't a five year plan, and production quotas, but we get there.
