The OP is confusing things a bit by conflating "yield to maturity" with "interest rate." Yield to maturity is the total return for the bond holder if they hold

The OP is confusing things a bit by conflating "yield to maturity" with "interest rate." Yield to maturity is the total return for the bond holder if they hold until it matures. That includes market/auction price, par (redemption) value, periodic coupon or fixed interest payments, and the time to mature. Expressed as a percentage thats "yield rate." That total yield rate will fluctuate on the secondary market based current prices or initial competitive auction prices. In short, for holding bonds you almost definitely care about total YTM and not the face coupon/interest rate.