What happened to the artificial-intelligence revolution?

In the world’s tech capital it is taken as read that AI will transform the global economy. But for ai to fulfil its potential, firms everywhere need to buy big tech’s AI, shape it to their needs and become more productive as a result. Investors have added $2trn to the market value of the five big tech firms in the past year—in effect projecting an additional $300bn-400bn in annual revenues according to our rough estimates, about the same as another Apple’s worth of annual sales. For now, though, the tech titans are miles from such results. Even bullish analysts think Microsoft will only make about $10bn from generative-AI-related sales this year. Beyond America’s west coast, there is little sign AI is having much of an effect on anything.