The majority of my African folks are left out of the banking system when only a few medium class chaps thriving in business, working for multinational or relatives of politicians and politicians themselves can actually afford or deserve owning a bank account, a debit or credit card.
The majority is left out because they are alleged to be unbankable and are therefore forced to deal with cash, they cannot afford or have access to any credit, which eventually helps keep any bubble out of the real economy. Ergo, nearly no one borrows from the future to spend today as oppose to citizens in the US and in most of the West.