You're on line at the supermarket, and the little old lady in front of you with her eggs and cheese is asked for her loyalty/discount card. Do you think she'll be faster pulling out a piece of plastic, or navigating through her mobile phone from menu to menu to app to option? And the same again if she's paying by credit card.
Credit/debit payments are gaining a foothold, but it's going to be a loooooong time until we even consider a cashless society.
And there's few things more enjoyable than giving real cash to a little niece or nephew.