There’s nothing new about buying now and paying later. You can do it with lay-by or a credit card. But the version of it invented by Afterpay, and copied by so many rivals, is so different and so hugely popular it’s not surprising it’s raised eyebrows.The most obvious reaction is to see it as a new way of tempting young people, in particular, to overload themselves with debt and make their lives a misery. The government should...