tl;dr: Thomas Ptacek is leaving Fly.io to build an AI-native phone with Kurt, arguing that AI will dissolve the boundary between programmers and users, leading to a world where most apps are personal, disposable creations built on-the-fly rather than prefab software from strangers. He contends this makes traditional operating systems—designed to sandbox software from untrusted third parties—obsolete, and that today's phones are still rooted in a 1970s paradigm of running fixed-function applications. The new device won't run traditional apps; it'll generate them on demand from user prompts.