If a person pays to purchase a bond with their own money they get that money back when the bond is paid. If they borrow to purchase it they of course need to pay whatever balance is left on such loan. If a bank or central bank creates money to purchase a bond and it is paid off that money goes “poof”.
The money creating function of private finance is misguided, unnecessary, dominating and ultimately de-stabilizing of the economy. We must have a publicly administered national/central banking system and policies that implement the new monetary, financial and economic paradigm of Direct and Reciprocal Monetary Gifting in order to have a humane economy, a money system that truly serves us instead of dominating us and in order to be able to finance human and planetary survival.