I’m assuming the poster doesn’t speak English as a first language, so I’m hopeful it was a more innocent question than the racist dog whistle it seems like at first glance.
I can see why one might be curious about the economic comparisons between different geographic spaces with vast sizes, even though it’s almost impossible to really answer.
I’m not feeling as charitable as you. The fact that they started with “no offense” tells me they know they’re saying something offensive. I think it’s a way of saying "Sure they’re geographically big, but they don’t contribute as much to the world as western (white?) countries.