It is best to have less than three personal cards. Too many credit cards will easily lead to overdue credit cards, and some banks will check the user's credit information every time they apply, which will have a great impact on future applications for mortgage, car loan and credit loan.
If you want to apply for multiple credit cards and maximize the number of credit cards, you must plan the application order, because each bank has different sensitivity to the total amount of credit and card issuers.