And they can do this without a federal government backstop, just like an SP500 ETF does or a US Treasuries mutual fund, or an REIT, etc.
My point is the federal government need not provide a subsidy to these businesses that "invest" customer's money (or simply handle the underwriting of loans in many cases).
Right now in the US, via the Fed Funds rate, the federal government pays a business 5.5% just so the business then turns around and pays me 5.05%, all for keeping an entry in a database. And these businesses pay a lot of less discerning depositors a lot less. Surely the federal government can just give all 5.5% to people directly.