You hate it but companies love it because people having easier access to spending makes them better consumers I guess?
Very specific industries like amusement parks see some gain, but overall the economy would be far better off with significantly smaller credit card limits.
Take that same person and remove the impulse buying at 21 and by 28 they will have saved that money to make those same purchases and not have to service debt after that point or try to dig themselves out of a hole.
Even if they end up saving the money for years, it’s likelihood to end up as a down payment on a house or something. Because the economy isn’t just individual purchases it’s the average activity across generations at each individual moment.