Yes, they use credit cards for almost everything and I think it's expected of them to have one when they become adults.

An american can explain this better than me.

Even apart from its necessity for getting bank loans at reasonable interest rates, most landlords check your credit score before renting an apartment or house to you. If your score is low you'll have trouble finding anywhere to live and you might have to live in your car ... if you can even afford a car without getting a bank loan for one.

Most Americans can't afford a $400 emergency and live pay check to paycheck. Car breaks down, emergency medical expenses, emergency house breaks down could all cost over $400. You need a Credit card for that back up that you could eventually pay back by probably sacrificing something else. Need a car need a credit score or you pay $3-10,000 more in interest same with buying a home. Want to rent need a credit check. Want to get a job at a bank, military contractor, some government positions, and other secure jobs. They want to make sure you don't have bad credit or can't be taken advantage of . Which no credit is often considered bad credit.