New Delhi, Aug. 11 -- The artificial-intelligence revolution is supposed to improve the financial fortunes for companies in a wide swath of sectors. AI should help businesses cut costs and make them more efficient, lifting profit margins. So far, however, things aren't playing out that way.

Torsten Sløk, chief economist at Apollo, noted in a recent report that the net profit margins for the technology and communications services sectors have gone up since the end of 2022, which is when OpenAI introduced ChatGPT. But margins for numerous other sectors, such as healthcare, consumer staples, energy and materials, are either flat or down over the same period.

In other words, Nvidia and the hyperscalers in the Magnificent Seven are bene...