I've had a credit card for over 10 years and get roughly 3% back on average which comes out to thousands of dollars each year. Never once have I paid any interest or fees. It has helped build my credit which is a big part I have over a 800 credit score. The money automatically is paid each month out of my bank account, I don't have to manually do anything
> The US is the only country in the world where you have such a credit history system built with credit cards.
Aside from the links posted in a sibling comment, I wouldn't say the U.S. credit system is built with credit cards: it's a fairly holistic metric that takes into account rent payments, loans, and a bunch of other stuff like "bankruptcies, foreclosures, lawsuits, wage garnishments or attachments, liens, or public judgments against you"[0]. Credit cards are lines of credit, so they certainly factor in, but the focus on your overall credit health, of which your credit cards may be a small part.
What exactly are the downsides I've had?