This argument is being framed incorrectly. It's the fundamental discovery that counts, not the implementations. The discovery of steam power is more important than Hero's Engine because discovering that you can do useful work with steam allows you to build all kinds of things that didn't exist before. Having a whirligig that runs on steam gives you nothing more than a few minutes enjoyment. Guns are definitely not a refinement of throwing things, someone who only knows how to throw something cannot build a gun. Guns are a refinement of the invention of gunpowder and good enough metallurgy to produce the gun itself. Similarly, rocketry is a refinement of gunpowder and the discovery that pressurized gasses escaping from a hole or nozzle can propel something. A smartphone itself is not a truly novel discovery, it's essentially a handheld portable computer. All the same technology exists or could exist in other form factors. If we compare it to something simple like a hammer, it is just a small hammer good for doing certain tasks and not others. It doesn't compare to the discovery that if you attach a weight to a handle you can hammer things. There are other specialized forms of hammer that are better for other tasks. i.e. a smartphone is just a specialized form of computer.