Why Does Your Stablecoin Balance Grow if the Price Stays at $1?

The courier puts $100 of backing into lending; the borrower repays $102, including $2 interest; the issuer converts the interest into two new tokens; the courier credits the wallet, raising its balance to 102 while price stays $1; the user redeems the two extra tokens, which are burned; the courier pays out $2 and returns for the next cycle.