I think you take the "create money out of thin air" expression too literally. They get money from depositors and they loan it out. That's how money appears to be created since both the depositor and the borrower act as if they have the money.
That is because they _do_ both have the money. New money is absolutely created by the act of making the loan. I do not take the expression too literally. You are mistaken. Please read what is occurring before you make further incorrect assertions.
My mistake is considering the monetary base to be money and the rest to be imaginary. In a way that is true, but if it walks like a duck and it quacks like a duck ...
Bitcoin is simliar in a way. Bitcoins don't exist in the sense that they are tangible or that they are even stored somewhere, but somehow you can still transfer them.
I would say that the main difference between bitcoin and fiat is that fiat fundamentally represents debts while bitcoin represents capital.