Apple built its empire on control. It also made Apple the world's top-valued company for much of the past decade, a position only overtaken by artificial ‌intelligence chipmaker Nvidia in 2024. But when incoming Apple CEO John Ternus takes over from Tim Cook this fall, he will face a question that is key to the company's survival in the AI age, testing the limits ​of Apple's practice of curating which apps and services can tap into its hardware.