Hamilton in Federalist No. 9 adds space to the New Science of Politics, which includes ideas like a constitution, checks and balances and a representative government. A republic can succeed in a large area because it gives citizens opportunity, a place to start over and become someone different and find new opportunities.
Banks are holding trillions in excess reserves and are getting paid .25% interest payments by the feds to hold them. Banks aren't loaning reserves to small businesses because the interest payments are a lower risk investment. These profits go to bank stockholders. Who decides on these policies? Representatives from bank stockholders.