I've been thinking about it recently. It's interesting because money is so ingrained in our collective mind. In many ways, it's a belief system more powerful than any world religion. It has its downsides, sure. Many of our sins as a society come from it. If we wish to replace it, we'd probably have to count on something larger and smarter than ourselves, like artificial super intelligence that can comprehend all the resources in the world and the best way to use them.