There’s some debate about whether plastic credit and debit cards will be totally replaced by mobile payment systems in the next few years. However, there’s no doubt that, in 2030, my son will carry a wallet with cash in it, because we’ll still be using paper and metal money well into the future.
In the information age, paying by cash is the best way to keep your purchases anonymous. Aside from simply preserving your privacy, paper money is a great shield against identity theft, because the payee doesn’t even get your name, let alone an account number. The government would probably love to end the use of cash, because it allows payees to keep illegal transactions off the books, but paper money is the only form of payment that doesn’t require a third party like a bank to get involved.