As for CEO payments, auditors. But in general CEOs reward themselves by issuing debt (bonds) to cover stock buybacks, to boost stock price, to which their bonuses are tied. Calling this kind of activity fraud is to some extent true, as outside the US a lot of this kind of thing is regulated.
Banks could be pure digital banks that have a employees in the hundreds. Typically they are dinosaur institutions that employ in the 10s or 100s of thousands of people. The banks use fees and interest to cover the cost of employees mainly. Incidentally, this is one reason why governments chose to assist banks in 2008. Directly and indirectly they employ a big chunk of the economy, a consequence of Western deindustrialization and financialization.