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...

I’ve got a high credit score and I’ve never not paid it off in full. It's only really ever went up over the years, with the occasional tiny 1-3 digit drop. I'd never pay interest I don't need to in exchange for a higher rating; they've got enough money.

Yeah no. Pay the entire statement balance every month, that's the whole point. If you want to do debt stuff I guess you can get a mortgage or a car loan or a school loan, but these are not requirements for good credit. You use the card, you pay the card, you now have 100% on time payments and probably low credit utilization. Get a card early so average account age high if you can, and don't get lots of hard credit checks in a row.

You can literally get free credit checks through most banks or directly from places like Experian and see what it is that affects your particular score.

Don't pay 18 or 25% interest on anything, that's nutty.