Here’s why tablets (yes, tablets!) will replace the smartphone

I’m sure to get the “you’re off your rocker” commentary on this one, but I make a living by looking ahead in the world of mobile technology. And what I see now is a trend that I have watched build for nearly half a dozen years. Thanks to the pace of mobile-network expansion, new audio and video technologies, the expansion of Wi-Fi, and more-capable hardware that runs longer on a single charge, I expect the tablet to begin replacing the smartphone within the next half a dozen years. There, I said it.

Hopefully you’re either done laughing at me or you’ve refrained from the “no way, you idiot!” comment and are still reading. Cool. Now I get a chance to explain my thoughts so we can have a useful conversation on the topic. We can agree to disagree, but there are a few reasons I see this happening.

Our dependence on mobile media consumption is growing

This won’t surprise anyone, but now that traditional video — think movies and TV shows in addition to YouTube(s goog) content and the Olympic Games — is more readily accessible on mobile devices, screen size and video quality become more important. Why watch the content on a small, low-resolution screen when you can watch it on a high-definition screen that’s still easily portable? There’s just no point in doing so, nor is it likely to be preferred.

I believe this reason has already been driving the desire for larger smartphone screens, not the need for more components in the devices nor bigger batteries, although that’s a nice side benefit. People want to have a not only mobile but also immersive experience. Don’t take just my opinion on that: See T-Mobile’s recent survey showing that 77 percent of the respondents want larger smartphones. And I may be reaching on this, but I’m not surprised that Amazon(s amzn) rolled out its Instant Video app for the iPad before bringing it to the smaller screens of the iPhone and iPod touch.

Voice on a tablet isn’t as bad as you’d think

I know this because I’ve done it. I took my Galaxy Tab 3G with a data-only SIM card and used it as my primary phone for a few months and later did the same with my Galaxy Nexus phone. To do this, I had to set up Google Voice and Skype(s msft) forwarding, but in the future it won’t be a difficult prospect. In fact, the original Galaxy Tab actually has cellular voice capabilities, but the U.S. carriers stripped it out. In Europe, I know several people who used the Tab as their main phone.

Sure, you’re not going to hold up the tablet to your ear. I have done that before just for fun and I deserved to be laughed at. Not because it looked stupid, however, but because I wasn’t taking advantage of simple options such as the speakerphone, wired headphones or Bluetooth headsets. These solutions have been around on phones for years, and guess what? They still work. Additionally, our use of video chat continues to grow, which brings me back to the immersive experience: Why see just a small, low-res picture of who you’re chatting with when you can see a larger, high-res video?

One more related aspect: Voice calling has moved far beyond the traditional phone. As Nimbuzz hitting 100 million users this week shows, we want communications to come to us, regardless of the device we use. These days I make and receive more phone calls from my computer than I do from my phone. Google Voice routes the calls to where I’m working and the device I’m working on, and I simply take the calls from my Mac, PC or Chromebook. When not working, those calls can be routed through any number of VoIP services to other phones or my tablets. The same applies to video. Thinking of the phone as the central method for communication is like thinking today’s living room is the central place to consume entertainment content.

The user interface is moving beyond pocketable screens

Look at how voice interaction is starting to become part of our digital world. We’re in the early stages — from an end-user consumer view, that is — of speaking to our devices and having them follow our commands or look up information. This trend is going to pick up steam, and I’ve even gone on record that audio-control platforms such as Siri could become the invisible interface of the future. Instead of different visual platforms, icons to tap and pages to navigate, the common denominator can be speech.

It’s actually happening today in automobiles, and that’s a key example. Why? Because although we shouldn’t be using our smartphones or our tablets while driving, cars are using the apps and connectivity of these devices for in-car entertainment, directions, social networking and more. All of a sudden, the screen size matters less because we’re not looking at the screen. So we won’t need a smaller device to tote when driving or doing other activities.

Tablets can do the same things as smartphones, only better

I always turn to my tablet before my smartphone if possible. Why? The tablet experience is simply better for browsing, apps, email and nearly everything else I can think of. Much like we’re shifting computer tasks to mobile apps on devices, our smartphone activities can easily shift over to tablets for this reason. My podcast co-host Matt Miller noted this in a post illustrating what smartphone activities he has migrated over to the Nexus 7 tablet, and I suspect that list will grow in the future.

In fact, I can’t think of a single digital activity that’s better on a smartphone than on a tablet. You could reasonably argue that voice calling is, but my suspicion is that most who say that haven’t yet tried to use a tablet for such communication. But GPS navigation? Web browsing? Gaming? Reading? With few exceptions — say, capturing photos or video — I think most will say these are better on tablets. And they are activities that are likely to improve even more; the tablet market is in a far earlier stage of its maturity than smartphones are.

Naysayers are still judging based on today’s use cases, not tomorrow’s

So the obvious main retort to my thought process is surely going to be, “But you can’t put a tablet in your pocket! Who’s going to carry a tablet everywhere?” And my answers are, “So what?” and “You will, and if you don’t your kids will.” Simply put, we can’t think about today’s constraint of needing to put a mobile device in a pocket. We only put phones in our pockets when we’re not using them. Guess what? We’re using them more and more, which means they’re in our pockets less and less. Another observation? I’ve read comment after comment of people saying “I take it everywhere” after buying a 7-inch or comparably sized tablet, even if they were never interested in the form factor before. And on a nontechnical note, I remember carrying the old DayTimer paper organizers; think of a personal digital assistant that wasn’t digital at all. It couldn’t fit in a pocket and yet it went everywhere.

Think about tomorrow’s world: As the demand for apps, the mobile web and cloud-stored data increase — something that’s already skyrocketing — we will be connected more and more in the future. Will we be constantly staring a mobile device? Probably not, as we’ll still need to walk around without bumping into things or getting run over, but that’s what Google’s Project Glass is all about: Staying connected while on the go. My point is that in the future, we will surely be relying on our mobile devices more than we do today. And just five years ago, the “take everywhere” device for most people was a laptop. Now we’re gaining laptop-like features on tablets that are easier to carry around and last all day on a single charge.

So when will this happen for you?

It’s possible you have read this far and still think I’m whacked. No problem; I don’t take it personally. My goal is to consider the future, get the conversation started, and have you help me consider this possibility. And this isn’t about the iPad versus the Nexus 7 or any other tablets on the market. Buy what you want and use it how it best suits you. But I urge you to see what I think is the writing on the wall. It may not be our current generation that can get past the pocketability of a phone, but I suspect it will be the next one at the latest. After all, you couldn’t pocket the first phones either, and look how that turned out. And if you need another example, just look at how well the 5.3-inch Galaxy Note is selling alongside rumors of an even larger follow-up product.

How will we know when the tablet begins to replace the phone? I’ll be keeping any eye on the sales of both devices. Once tablet sales approach those of smartphones, we’ll see the inflection point of change. I give it five years.