Ever notice the shape of airplanes since the 70’s? It’s not like we’ve “innovated” them into being flying saucers. There is a LOT of low-lying fruit in any product design. Eventually, you sort of figure precisely where things should be to make customers happy. So, you go to a website and click “add to my cart” a bunch of times. Where do you move your cursor to find that cart? Top right-corner, right?

Human computer interaction has a maximum design refinement that eventually lands on certain heuristics. You get to that point, and you don’t have anywhere else to go. Some of this is built upon the reinforced expectations (the shopping cart being at the top-right corner), some of this is based on the physical form/shape of the human body. But in the end, all you’re left with in phone design is a few choices of rectangle-ish shapes and slowly, slowly, slowly refining factors on the edge of the design.

Those factors will slowly but surely eliminate any physical changes. Eventually we removed sharp corners. Eventually we made the screens pressure-sensitive. Eventually we removed physical jacks. Eventually we removed all buttons. This is the way of things. After we do all of that, what’s left?

Software features and processing power. Sure, we want better batteries, but the truth is, we’ve really gotten fairly close to the maximum chemical properties of battery design. In 10–20 years, we’ll finally get nano-capacitors that can be mass-produced and give you battery life on the order of weeks. Until then, it’s software innovation and internal engineering.

But on the outside, every new generation will differ in shrinking proportions from the previous because all the design heuristics have been worked out. The only place to go will be features. Eventually, your phone will be your personal assistant and will be essential to navigating the world we’re building from instantly paying your bills to managing your interactions with automated system. But 25 and 50 years from now, I don’t expect the “phones” to look all that different.

I think Apple knows this. I think they know that the future of their products is in integrating their technology and Siri into all aspects of your life. It will be an ecosystem of information that is built around you. The future is software and getting you to live through Apple products, not just the phone.