It is not as if Ancient Egypt didn't build complicated irrigation systems too. There is survivorship bias embedded in your reply. Pyramids are extremely durabl

It is not as if Ancient Egypt didn't build complicated irrigation systems too. There is survivorship bias embedded in your reply. Pyramids are extremely durable, so we can still see them and judge them. Cultures that didn't build them could well spend their money and effort on some other status symbols, which were more transient. Like huge events (balls etc.) held for the royalty.