Early PCs lacked two things that made smartphones a whole new ballgame: a network, and software. When the Altair 8800, IBM PC, Apple II, Commodore PET, and Tan

Early PCs lacked two things that made smartphones a whole new ballgame: a network, and software. When the Altair 8800, IBM PC, Apple II, Commodore PET, and Tandy TRS-80 shipped (1975-1980), there was no way to communicate with other people, nor was there much software (nor was there convenient storage for it — cassette tapes and floppies were severely limiting and a major pain to use). If the machine didn't have a Basic interpreter, it was neither useful (little software), nor engaging to the hobbiest (no way to explore the machine). By the time smartphones shipped, communication with others and availability of vast repos of apps were almost unlimited. Only a tiny fraction of owners ever thought about coding up their own apps or exploring the infrastructure of the device. And of course the makers of smartphone OSes had no intention of opening up their sealed gardens so users could compete with their near-total control of the user experience — a lesson that Microsoft's domination of the PC's OS taught to all budding monopolists.