It&#x27;s all about the I&#x2F;O.<p>Mobile&#x27;s Achilles&#x27; heel is that touchscreens can&#x27;t be The One True Interface. Finger touches are too vague, involve covering up too much of the screen while you do it, and involve too much imprecision to be the only input. In a nutshell, despite what your initial analysis might indicate, a touchscreen interface is getting too many fewer bits than a conventional desktop, especially as conventional desktops and notebooks grow touchscreens. Voice still seems to be having a hard time covering the gap, making for good demos but definitely having a hard time breaking out in general (i.e., note how you still have to <i>invoke</i> voice on your phone, it is not fluent).<p>They especially can&#x27;t be the One True Interface on a phone&#x27;s screen.<p>Barring some breakthrough, I actually think what we have now is what we have for the next 5-10 years. Yes, there&#x27;s a lot more mobile apps to be written, and the numbers for mobile are going to continue to climb, but I think they&#x27;ve largely done their damage to desktops and notebooks now. See how the luster of tablets has also faded.<p>(The next breakthrough will be phones being able to practically take over notebooks entirely, but despite the steady stream of prototypes we&#x27;re not seeing any traction. It seems to be hard for a mobile OS to take over all duties of a desktop and it seems to be hard to jam a desktop OS on to a mobile. And it&#x27;s not strictly speaking the OS, but the app model, security model, monetization model, etc. There&#x27;s a lot of subtle conflicts between those two worlds right now. I think the instinctive closing of the ecosystems is a big problem here. Note how we&#x27;re still klunking along with things like Chromecast, where in a truly open ecosystem we ought to simply have a generic display protocol that our phones could both produce AND consume. There&#x27;s still this deeply foundational idea on all sides that <i>they</i> are the master. Why can&#x27;t I use my phone or tablet as another laptop screen? Why can&#x27;t I use my laptop screen as an adjunct to my phone? Why is all my IO hardware so, <i>so</i> very stuck to the hardware that happens to be in them? Is that not a step backwards from the desktop world itself? Answer: Nobody can make any money from standards open enough to solve this problem; if the hardware isn&#x27;t the &quot;master&quot;, it&#x27;s not making money. The mobile world needs a heaping helping of free software, but it&#x27;s not clear how to get it there.)