It’s the “out of thin air” or

It's the "out of thin air" or "at the stroke of a pen" part that's important. It's only because bank deposits are included in the defintion of broad money that the money supply rises and falls with loans being issued and repayed. You have to bear in mind that the type of 'money' that is created by a commercial bank is different from the base money that is created by the central bank. To understand how the money system works you have to appreciate the different measures of money M0, M1, M3 etc.