A bank is a broker between the middle class and the rich. The only place where the two meet is in a bank. The middle class brings the money, through saving, and the rich takes it, through borrowing. A middle class person saves the money because they have more money than their thinking capacity. So they keep the money in the bank so they can go and think what to do with the money they saved._
On the other side, the rich people come to pick that money, through borrowing, because they have more ideas than the money they have. On a practical side, please show me one billionaire who got rich through saving and I will show you a million Indians who have money saved in the banks and are still renting the houses that the Millionaires and billionaires build through the middle class people savings which the rich borrowed from a bank.