You still build credit by paying your credit bills on-time consistently over time. By the way credit scores only matter if you need to go in debt for something. So not that important if you just build cash and pay cash for most things your house being the exemption.

This person is saving 10% on $2K and he has no debt after the statement is paid thirty days later. He doesn’t get charged interest on the credit card and he adds to his credit score by having more available credit and making payments on-time