With a few days to go before the 2016 Mobile World Congress, now's a good time to take a look back at 2015 and assess how the mobile industry has evolved since its last big get-together. One trend emerges from even a glancing retrospective: smartphones are as important as ever, but they aren't grabbing the headlines the way that they usually do.

The standout stories in mobile hardware over the past year have been Samsung's Gear VR, camera dongles like the DxO One and Flir thermal imaging camera, and keyboard attachments for tablets like the Pixel C and iPad Pro. 2016 has kicked off in the same spirit with the biggest excitement so far being reserved for the Bragi Dash wireless ear buds and Apple's rumored dropping of the 3.5mm headphone jack in the next iPhone.

LG is staking its fortunes on a modular phone

After years of improving at a breakneck pace, the smartphone is now coming to terms with its maturation. It's a basketball superstar that no longer has the athletic ability to wow the entire globe by itself — and the time has come for the supporting cast to step up. LG is set to lead this charge at MWC with what looks like the most ambitious modular smartphone to date. All prior attempts at making smartphones with plug-and-play components have either been niche, startup endeavors or exploratory, not-yet-commercial ventures like Google's Project Ara. LG is staking its fortunes on a flagship whose distinguishing feature is the things you can plug into it. Accessories.

This is, of course, not a sudden or unexpected change. The mobile industry moves quickly, but it does so in a predictable rhythm. Samsung has enjoyed great success with its Galaxy Note ever since the first edition back in 2011, introducing a stylus as a distinguishing (and evidently desirable) feature in the phablet market. Apple's iPhone and iPod have spawned and supported an entire ecosystem of third-party dock and case manufacturers, and the Cupertino company has been expanding its accessory business with the acquisition of Beats and the launch of its own battery case in 2015.

Profits in the mobile business are shifting right along with the opportunity for greatest innovation. At a time when even entry-level smartphones can feature unibody metal designs and decent cameras, distinguishing a device through its hardware alone becomes next to impossible. The differentiating features move from the physical core of the smartphone to its periphery and peripherals. LG wants to sell a unique smartphone and so it's building out a unique accessory ecosystem around it. HTC was one of the first companies to recognize the potential to differentiate with good accessories, but it never quite struck the right formula with failed experiments like the Boombass.

The iPhone and Android can't be disrupted, but everything around them is up for grabs

Today, we're staring down a future where portable headphones, external battery packs, camera modules, and clever keyboard peripherals will hold more intrigue and potential for disruption than smartphones by themselves. And who can forget about smartwatches? Together with other wearables, their best present use is as an extension of the smartphone. And even as interoperability is improving, for most people buying an Android Wear device or an Apple Watch will add an extra anchor keeping them in either Google or Apple's ecosystem.

What every mobile manufacturer wants is differentiation, reasons for people to choose to buy its hardware. For a long time, those could be provided through hard specs like high-resolution, optically bonded displays or just superb cameras — Samsung and Apple's success is testament to the fruitfulness of that strategy. But such advantages have to be refreshed with every single iteration of a device, and technology just can't move that quickly for that long — so now everyone is turning to the question of what unique extras can be connected to the smartphone to make each one a unique proposition.

It's a nice phone, but what can you plug into it?

Apple's reported Lightning headphones plan is as much a practical optimization of space use within the device (the headphone jack's absence would open room for other components) as it is a deliberate ploy to keep iPhone users locked in. No other company could possibly get away with such an audaciously inconvenient change, but Apple has the scale and established user base to at least attempt it. LG is similarly betting on external components making its next flagship distinct from all the others. And Samsung has built a flagship-like series around the Galaxy Note and its S Pen stylus, while also forging ahead with the Gear VR as a differentiator for its broader lineup.

The upcoming MWC will be graced by a multitude of awesome new smartphones from a vibrant and thriving marketplace. There's no question of smartphone innovation halting anytime soon, but it's obviously slowed down. Accessories and peripherals are picking up the slack, offering greater potential for hardware differentiation and profit, both in the short and long term. What that means for us is that all the most interesting questions in 2016 will probably still relate to the smartphone, but reside outside the device itself.

Check out LG's radical new flagship phone, the LG G5, which takes modular accessories to a whole new level: