"A confluence of forces is behind Big Tech’s business-model ferment. Blowback over privacy abuses and misinformation threatens ad-driven strategies at Facebook and Google built on harvesting people’s information and maximizing the time they spend glued to the internet. The Smartphone, which underpinned so much of the tech industry’s boom over the past decade, is maturing, with incremental innovation and flagging sales. And the law of large numbers, combined with the tech industry’s history of upstarts leapfrogging incumbents on innovation, compels executives to seek out new places to disrupt, lest they themselves be disrupted.

Still, as they stretch into new domains, tech’s titans increasingly bang into each other. Amazon’s advertising effort is impinging on Google and Facebook, both of which are also muscling up against Amazon in e-commerce. Facebook’s messaging shift threatens Apple, whose Messages app is important to its services push. So do Amazon and Google’s forays into hardware. Apple’s Hollywood campaign encroaches on Amazon, which already spends billions of dollars annually producing entertainment.

Peter Barrett, a veteran tech executive who co-founded venture investor Playground Global, says the shifting business models could reorder the dominance of the tech giants. The rise of new technologies like voice assistants that build on or displace the smartphone will help determine which established companies — and which new players — thrive. “Some will make the transition,” he says, “and some will see their power eroding."