To build on this: One might ask, why don't countries with larger populations directly derive more wealth (particular by measurement of GDP) than smaller populations naturally?

There are a lot of reasons for this, but the short answer is that health, education, and enough individual wealth to explore figuring out ways to generate new revenue streams is important. Authoritarian countries are by nature not able to do this due to limits of their authoritarian nature, not necessarily limits of their population numbers.

It's all intertwined :)