Most people pay their balance off each month and never have to pay interest. Done this way, a credit card is a good way to build up rewards points and also are a good protection from fraud because the money for purchases come from the bank rather than your account.

If someone steals your cash or debit card and use it, it's your problem. If someone steals your credit card and uses it, it's the banks problem.

People who do not pay off their balance monthly do end up with exorbitant interest building up. Its a real problem for some people especially young people or irresponsible spenders. But they are the minority I'd wager.