It’s good to have friends. They come to your birthday party, offer a shoulder to cry on when things are hard and spend precious corporate resources developing apps for your nascent virtual reality platform despite little direct return. It can be tempting to believe that a pile of cash worth $30bn, and a single product line that brings in more than$200bn a year, is an acceptable substitute. But Apple is learning that money can’t buy you everything. Last week, pre-orders opened for the company’s Vision Pro h ...