also note that the primary difference here is that you would consider your Steem as already part of the money supply, even though you arent actively using it. Whereas you consider central bank money as coming in from the outside.
But all youre showing at the end of the day is that if enough people are willing to borrow money, then leave borrowed money sitting in the bank, that the bank can make a killing lending out the same borrowed money over and over. The accounting is different with a 100% reserve, but it depends on the same thing... multiple companies being willing to let the bank hold money that they borrowed.
Further side note... this is why when the fed wants to decrease money supply, they don't hike up the reserve rate, they hike up fed interest rates... that way its more expensive for banks to borrow money, so they have to be more selective about who they lend it to (or they have to charge more interest) so the demand for loans decreases.