The future of computing is not a chatbot in a browser — it is a native Agentic OS that operates ambiently and autonomously, understanding real-time context: where you are, what you see, who you're talking to. That rich sensor data lives almost entirely on mobile devices and wearables. Because Microsoft lost the mobile platform war, it does not own the glass that users look through. Attempting to build a fluid, ambient AI ecosystem on a stationary OS is fighting a 2030s war on 1990s terrain.