OP is clearly presenting a simplified picture for sake of discussion, which made me wonder what populations or regions he might be leaving out.
– Most populous continent not discussed: Africa [1]
– Most populous country not discussed: Indonesia [1]
– Biggest economy not discussed: Japan [2]
[1]: https://en.wikipedia.org/wiki/World_population
[2]: https://en.wikipedia.org/wiki/List_of_countries_by_GDP_(PPP)