Isn't that just not true?

https://www.capitalone.com/learn-grow/money-management/credit-myths/

Myth No. 5:  You have to carry a credit card balance to build credit

If you don’t pay your credit card balance in full, it’s carried over to the next billing cycle and considered a revolving balance. And that unpaid balance might accrue interest. 

You don’t need to carry a balance to build credit. According to the CFPB, “Paying off your credit cards in full every month is the best way to improve a credit score or maintain a good one.”

Fact No. 5: You don’t have to carry a credit card balance to build credit

While carrying a balance isn’t necessary to build credit, a healthy credit utilization ratio—which measures how much available credit a person is using—is an important part of credit. 

In addition to paying off credit card balances in full every month, the CFPB recommends keeping a credit utilization rate of less than 30% of your available credit. That can be a way to show you’re responsible with credit.

I pay my credit cards in full every month and accrue zero interest and have excellent credit...