Bank transfers are free because you have to deposit (aka lend) money to the bank before transferring it. And the bank get to use that money for profit while it

Bank transfers are free because you have to deposit (aka lend) money to the bank before transferring it. And the bank get to use that money for profit while it is deposited. There's a billion dollars difference between a million and a billion. You can't just plop a billion dollars into your checking account. It's part of a hugely complex context (how would you even accumulate a billion dollars to deposit?)