Productivity is a highly subjective thing, but it keeps getting sold like a thing you can hold.
Tech companies love the word "productivity." It gives warm fuzzies to people in charge of things who believe it's a measurable thing that means more money, either through faster delivery of something or fewer human hours spent in the creation and delivery of that something. As a result a lot of tech companies try to sell productivity as a feature, and over the last couple of years few tech companies have been as obnoxious about selling this imaginary feature as mobile companies.
The truth is, productivity is not a feature to be tacked on and sold, nor is it a universal thing that everyone immediately has by using a specific piece of hardware or app.
I'm writing this editorial on my BlackBerry Priv, outside by my Weber Smokey Mountain on a perfectly dreary Sunday morning. Within arms reach is Google's new Pixel C, which I'm supposed to love because the clever magnets and Bluetooth keyboard make it a productivity machine. Don't take my word for it, ask Google. Yet here I sit, mashing away with only my two thumbs on a keyboard that is wildly less efficient than the nearly laptop-sized keyboard on the Pixel C. If I were to perform some kind of typing test, I'm sure the Pixel C would win out as the faster thing for me to type on every time. Typing doesn't equal productivity though, at least not for me. It certainly does for others. In fact you'd be hard-pressed to find a comments section or forum post about the Pixel C where the owner of one of these beautiful tablets is telling someone how great it is to be able to use it instead of a bulky work laptop or the screen on their phone. For some, the Pixel C could easily be viewed as something that increases productivity, but that alone isn't enough to sell this experience as a feature to everybody. After all, I'm still sitting here perfectly productive on my Priv and the Pixel C is still sitting to my left streaming The Martian from Google Play Movies.
There are half a dozen different ways I could be writing the words you are reading right now. I could be speaking them into a microphone with some speech to text translator over a Bluetooth headset, typing on my MacBook, sitting at my multi-monitor desk putting my CODE keyboard through another workout, or even just swiping the words out with SwiftKey, and I'd probably do all of those things before I put this Priv down and picked up the Pixel C and used the attached keyboard to write something. This has nothing to do with the quality of the keyboard, and everything to do with my personal workflow. The Pixel C isn't any more convenient than my current workflow in any of these alternatives, and so doesn't make me more productive.
Having the right hardware means using the right thing for your workflow.
If I sit down at my Desktop, which is arguably the most productive machine in my arsenal, I open myself to the heap of distractions also associated with that machine. Voice translation is great until an airplane flies over and messes up the translation, ruining my train of thought in the process. Laptops and convertible tablets require I be sitting in a specific position in order to comfortably use the hardware productively. SwiftKey is only productive for long typing sessions when I'm standing still or sitting. For me, right now on this Sunday out by the smoker, the Priv keyboard lets me walk around and type while keeping an eye on the temperature and enjoying my movie without sacrificing my train of thought. That makes it the most productive thing I can use right now, but BlackBerry could hardly get away with selling the Priv as a productivity machine for bloggers who enjoy smoking meat and watching movies outside, because that's a fairly small demographic. Instead, they just call it a productivity machine, even though there are plenty of people who would never find this experience better than what they are currently doing.
That's the thing many people don't consider when attempting to calculate productivity for others. Having the right hardware means using the right thing for your workflow. Smartphones are more productive than Desktops at times because of mobility. Desktops are more productive than laptops at times because of capability. Smartwatches can create a more productive environment by keeping you in the moment as you briefly glance at your wrist, while a pen and paper can be the most productive thing because you can use them without much risk of distraction.
The bottom line is productivity is a personal thing based on personal workflows.
All of these things are simultaneously the most and least productivity-focused thing in your arsenal, which is why trying to sell any of them as something to boost productivity as this thing you can have by owning something new is a mistake. Instead, these companies should be demonstrating successful workflows that can lead to increases in productivity. That's a lot more complicated to accomplish, due largely to a desire for these phones and tablets and watches to also be consumer devices to be used for fun. If you show the business professional getting things done, you risk turning away the 20-something with disposable income who likes it because it looks nice or because their friend has one.
The bottom line is productivity is a personal thing based on personal workflows. It's a goal to decrease the total number of steps required to complete a task in whatever environment you're in. Anything else is marketing fluff, and you're probably being sold nonsense.