If "everyone used to be poor," then how could some ancient civilizations afford to create massive buildings like the pyramids of Egypt and the Buddhist statues of Afghanistan?
a. Civilizations which controlled many poor people could concentrate their limited wealth and labor resources towards one giant project.
b. Ancient civilizations lasted for hundreds of years. The political stability afforded by such longevity outweighed the lack of wealth these civilizations had.
c. "Everyone used to be poor" is a general statement regarding economic history with some notable exceptions,
d. namely the civilizations which produced these monuments. Ancient civilizations usually operated under a single ruler, allowing for more efficient allocation of resources than under decentralized power structures such as democracy or competitive markets.