The smartphone has effortlessly replaced the PC as the centre of our digital world: last year one billion smartphones were shipped, accounting for more than half of all mobile phones sold.
And yet, behind the big numbers, there is uneasiness: the smartphone market in the US and Europe is already showing signs of saturation, and much of the growth elsewhere is coming through sales of cheaper models.
Adding to the pressure, companies' flagship smartphones are ageing and not especially gracefully — the iPhone is approaching its seventh birthday now, the Samsung Galaxy S series is almost four — and aren't generating the same levels of excitement they once did.
And while every new smartphone launches with a multitude of apparently must-have features, there's a nagging sense that, for smartphones, innovative has now been replaced with uninspired iteration.
I'd go further. The smartphone has become an innovation-free zone. What was the last great smartphone leap forward? The phablet, otherwise known as... a really big smartphone.
There are obvious (if not particularly good) reasons for this slowdown — the competing smartphone ecosystems are quite mature now and change is risky. Those small black slabs of plastic and glass are really supertankers in disguise: it's hard to change the direction of strategy due to the risk of negative effects on the broader ecosystem. Add to that the enormous costs involved in building and marketing smartphones make it very hard for new players to make an impact in the market.
As a result it seems that most of the excitement in mobile hardware has already shifted onto wearables such as Google Glass or the various attempts at igniting enthusiasm for smartwatches.
That's a shame, because there are still big problems to tackle with smartphones — and potentially exciting breakthroughs to be had, too. So in the run up to the annual Mobile World Congress (MWC) show in Barcelona next week, here are four that I'd really like to see engineers working on to inject some energy back into the smartphones market.
We are in the era of the anonymous black slab; there's almost no differentiation on form factor anymore. The smartphone is now such a design dead end that how the back of a phone looks is considered to be an important distinguishing feature. Curved and foldable displays could be manufacturers' salvation here: pretty much every phone maker has been working on these but they haven't yet managed to make them a must-have.
I carry around a wallet full of rectangular pieces of plastic with a few kilobytes of unencrypted, easily-lost data on them: credit cards. Sure, they're a lot smarter than they used to be, but all these cards still take up a lot more room in my wallet than an app does on my phone. Using phones for mobile payments has been dogged by competing standards and manufacturers, along with banks and credit card companies jockeying for position with the net result that nothing has happened fast. Getting mobile payments going would make smartphones much more personal again.
Phones are resolutely solitary characters and yet there is huge potential to make them work better with each other. I'd like my phone to do a much better job of sharing or interacting with my tablet, PC (or, in the future, my wearables). I'd also like them to do a better job of talking to other people's devices around me, whether that's sharing content or playing games.
Moore's Law advances haven't been matched by advances in battery life (something that's going to be an even bigger problem with wearables, of course). Getting more life out of smartphone batteries is a must-do for manufacturers. Modular design might help with this — something like Google's Project Ara or ZTE's Eco Mobius could help out by allowing you to add more battery if that's a key element for you while dropping something less relevant.
What do you think — which smartphone innovation would make the biggest difference to you?
ZDNet's Monday Morning Opener is our opening salvo for the week in tech. As a global site, this editorial publishes on Monday at 8am AEST in Sydney, Australia, which is 6pm Eastern Time on Sunday in the US. It is written by a member of ZDNet's global editorial board, which is comprised of our lead editors across Asia, Australia, Europe, and the US.