It is a marketing/advertising method, but sometimes there are special offers on those mailings that are worth looking at if you are in the market for a new card.
I will disgree with some above and say that credit cards are fantastic. (I am not talking about debit cards, only creidt) if you pay them off every month in full. You can get airline miles, or money back, or free hotel stays, depends what interests you. There are legal protections if your card is stolen, if someone steals your cash, it’s gone. During times when banks give decent interest (which granted is not happeneing right now) you don’t need to pay until 2–5 weeks after your purchase, giving you that time to earn interest on your money.
BUT, you have to pay on-time in full so you don’t incur any fees or interest. Over the last 20 years I figure I have saved a few thousand using credit cards all of the time, but I never buy anything unless I can afford it in full when I buy it. Also, I only keep a few credit cards so it is easy to keep track of, and my spending adds up fast on one or two cards, so I see the benefits quickly.