Wealth doesn't come from the belief that holding an asset will be worth more later; it comes from assets being invested in some way that makes them actually worth more later. E.g. I dig up some resource, and rather than consuming it I invest it in building some device that increases my ability to dig up resources in future. Wealth comes from productivity improvements.

Developed countries are wealthier because it takes a tiny fraction of human effort to produce e.g. a car or a loaf of bread compared to in a developed country, because through investing in technology/capital we're much more productive at making cars and bread.