Signs point to a long chain of great filters, as far as I can see:
- DNA/cellular Life itself: each is already highly improbable and hard to reproduce, and likely not even possible anymore in our current climate/atmosphere
- multicellular life is a lot more likely past step one, but still hard
- life that is maintainable and powerful enough to escape the struggle for survival long enough to bother with something like complex social structures and engineering (super unlikely because the more powerful you get, the easier it is for you to accidentally destroy all your food sources and starve to death until the system is balanced again)
My pet theory (completely unsubstantiated, of course) is that intelligent life is common but that it rarely develops money. Stuck with barter, most intelligent life never moves beyond low levels of trade and technology.
The concept of assigning value to largely useless objects and using them to keep score is extremely powerful, but also highly weird.
Have you read Debt: The First 5, 000 Years by David Graeber? While a lot of it is kind of... socialisty, it does a good job at describing how the standard "barter--> money" econ history is anthropologically wrong.
