Alright, if we want to get a little more real and less facile here, there is a hierarchy of capital stocks and flows which drives cost of capital for various players in the credit space.
Big, stable pools of capital have the lowest cost of funds. These come from banks with large retail deposit bases, big insurance companies, and pension funds.
Using that capital to create consumer and small business credit provides great risk-adjusted return on capital, but it has historically been a very sleepy area in terms of innovation and market responsiveness, and expensive to originate and service. The valuable innovation of online lenders has been to make the loan product a much better fit for the borrower, and to dramatically lower the fixed costs and enable smaller balance loans to become profitable.
The innovation and value add has all been on the capital deployment side. Sourcing capital still happens in the traditional way - lenders work their way down the cost of capital curve from equity, to expensive debt, to less expensive debt. The true P2P model without intermediation has turned out to be an interesting idea but of limited scope. As of right now, there is no better way to source capital than using the existing structure. It is pretty good and not obviously in need of innovation or disruption.
If an online lender were to do all the things that a bank does in order to gain stable retail deposits, it would become a bank with a typical bank cost structure. It's not obvious that there would be any advantage over the traditional bank model at this point.
If someone figures out an innovation that can source capital at or near the funding rates for big banks, but in a different way that involves a significantly lower cost structure, that would be a revolutionary change. So far there doesn't seem to be any way to do this.