The terms of the loan, in the bond, note or mortgage, specify that the money must be returned to the lender. If it is not paid on time, the collateral securing a note or mortgage becomes the property of the lender, who can then sell it and receive the money back. You could say that it gets Un-Created. There would be no sales, no production, and no employment in the economy. Of course debt pay-off is never ended in the real world.
Interest is the fatal flaw .
When money is lent into circulation, the lender usually wants more than the principal sum of the loan to be paid back. The return on loans is called interest. Think about that . When the music stops there's always someone who can't find a chair. So bye-bye baby.