There was a time when there weren't any credit cards at all, and later there came a time when credit cards were issued only to those that were deemed most credit worthy, whereas today credit cards are often marketed and issued to people of questionable earning capacity. We are taught nowadays that we need credit cards in order to establish our credit rating and to build up a good credit score, but what is often forgotten is the downside of not being responsible with your credit will destroy your credit score, possible preclude you from employment at certain companies, and stick you with debts that will be part of your life for the foreseeable future.
When it comes to the necessity of credit cards, we can say for a certainty that those of high income and/or deep assets don't have a need for a credit card, because they already have the wherewithal to pay for the things that they need with their income stream or assets. For those that make a decent income and/or have decent assets, credit cards are often not needed, but may be desired for those times when funds are a little tight or something unexpected comes up. Then there are those that are limited in both their income and their assets, who often may strongly desire to have a credit card, but most definitely don't need to have one, mainly because there is a near certainty that having a credit card will put them into a situation to which they will be subjected to penalties, high interest rates, and fees.
There is a fundamental reason why banks issue so many credit cards to so many people and that reason has absolutely nothing to do with people deserving credit cards or the like, and everything to do with the money that banking establishments make from the issuance of credit. While banks will make money even on people that pay their credit cards in full each month, by virtue of the fees that they charge merchants, and of which, incidentally, those costs are pass onto the consumer in the form of slightly higher merchant pricing; they make a lot more money from those that do not or cannot pay their credit card bill in full each month.
There is one other reason why credit is issued so easily to so many people in America and that is the inherent tendency for people to treat a credit card purchase differently from a debit card, or cash, or a check-issued payment. For whatever reason, and perhaps it simply comes down to the reality of it, when you pay for something with cash or cash equivalent, it feels real, because it is real, as that money literally has left your hands and will not be returning to you; whereas with a credit card charge that is merely a debit to your account, representing something that doesn’t have to be paid immediately, and consequently doesn't feel like money or its equivalent, instead it feels more like an exchange that benefits you.
The banks that issue credit cards understand the psychology and the lure of easy credit, and make it their policy to stick it to those that aren't capable of understanding that by their participation, they are playing in a game to which if they, the consumer, loses, they will have to pay penalties, fees, and high interest rates to the banks, to which it can be stated, just like in gambling, the house never loses.