Even if it was, there are better uses for a "decade with enough funding" unless you have some competitive advantage, like you're the CEO of Chase Bank or something. If you want to know how possible it is, consider that Bitcoin was released in 2009 and cryptocurrency's success at being used for payments - in the history of the world - it has been used for payments between people for something other than crimes, but adoption is way behind visa. Like, that alternative system exists (albeit not for free either) and there's no adoption. So the "billions" aren't exactly a market inefficiency. They make billions, but out of your life, how much do you pay to them. And then, do they perform a valuable service and charge money for that? Would you rather go to a bank and get cash and drive it to Amazon's local office, or mail them a cheque? For a fee, there are companies out there that will make it easier and faster and more convenient than that.