> why would people work hard without personal upside?

Define "personal upside" because people work hard all the time absent a path to power, or even material benefit! Come to think of it, why do people have children?

Humans are social animals and they are deeply moved to work extremely hard for the sake of love, dignity, and respect alone. Contrary to the nonsense picture you paint, humans only lose touch with such desires in the face of hopelessness to realize them.