Yeah, the transaction fees.
While we're aching from the transaction fees for Bitcoin, there goes the banks that have been charging a lot for the transfers that we do especially the overseas.
Also don't forget about the maintaining balance, we're obliged to reach that threshold and not to pass on that or else we'll be charged.
This is what makes financial institutions very wealthy.
And another thing is that they're backed by the government so being wealthy and at the same time powerful is what they are.
I can give an example of how they are supported by the state. For example, in some countries, the interest rate given to banks is lowered under the name of "policy rate". Even though the interest rate is lowered, the banks give loans to the public at a higher interest rate. They both buy the money they lend cheaply and sell it to the public expensively. This is not a positive side of the banks. In this way they are making the people poorer.