[friedman23]

The labor is a small fixed cost. Depending on what is done with the labor the leverage is potentially infinite (eg. many internet business that earn a million or more per year for every employee they have hired).

Growth can happen by getting the same labor to do something more valuable (maybe building houses instead of chairs?)

[sdflhasjd]

Labour is people, which need food and water.

[friedman23]

I don't see the point of your statement. Economic growth can happen even if the population remains constant (or even shrinks but that would be a headwind to overall economic growth and at that point it might be more instructive to look at gdp per capita).