They're not ... They're still smaller than the original cell phones ... And smaller than the "brick" phones. lol
Because people use them for everything except phone calls. Bigger screen to watch movies, TV, pics, etc.
If the government lets you have them by 2025 or sooner you should have a device on your wrist that will project (hologram) the time,temperature, gps, phone and many more useful items and no bigger than a wristwatch.