Apple CEO Tim Cook was the subject of an in-depth interview published over the weekend in The Washington Post in which he talked about a wide range of issues, including augmented reality (AR) and artificial intelligence (AI), the future of the iPhone, and the company's North Star. In the interview, Cook dismissed the idea of the iPhone accounting for two-thirds of Apple's revenues being problematic, calling the smartphone's dominance a privilege and expressing his belief that one day, every person on earth will own a smartphone. Cook also defended the company's progress in AI technology, pointing to the expanding capabilities of Siri, the digital assistant that Apple launched in 2011. Apple is opening up Siri to third-party developers so the technology can be used by other applications -- such as Uber or Lyft, as Cook pointed out -- to help users complete tasks faster and more efficiently. Earlier this month, the company reportedly bought Turi, a Seattle-based startup company and the latest purchase in a string of acquisitions aimed at bolstering its machine learning and AI capabilities.