There is a finite amount of land on earth, and a finite amount of most natural resources. We currently have no indication we will EVER develop faster than light technology.

Any discussion not grounded in those facts is a dishonest discussion. It is a zero sum game until those externalities change because ultimately our species is built upon extraction resources to produce wealth. It IS a zero sum game until you or someone else invents a means of solving the first order problems.

Isn't most of our economic growth based off inputs of energy (in the form of labor, electricity, etc) that ultimately derive from the sun, though, rather than primarily non-renewable non-recyclable resource extraction? The sun is technically a non-renewable resource, I guess, but only on cosmic timescales.

On a trillion year time frame, sure.