There is still a house and ship being built at the end of it. Money and markets are just an abstraction of the physical work. Just like when i write in python - at the end, there is physical work being done in memory and cpu hardware. Money and markets allocate capital and no economist suggests otherwise.
Derivatives, securities and other finacial "products" have no physical backing, they are purely abstract concepts. They don't even exist on paper now, just intangible bytes.
