Research and advisory firm Gartner said on Tuesday that it expects global smartphone sales to continue to slow over the course of 2016, essentially echoing what we've been hearing for the better part of a year now.

Gartner forecasts worldwide smartphone sales to climb just seven percent this year to 1.5 billion units, down from 14.4 percent growth in 2015. Roberta Cozza, research director at Gartner, notes that smartphone growth reached a high mark in 2010 at 73 percent.

North America, Western Europe, Japan and mature Asia/Pacific regions have reached saturation levels of 90 percent, Gartner said. Even China, which was targeted as a hotbed for growth just a few years, is cooling. At this point, anyone that wants and can afford a smartphone has already purchased one.

What's more, consumers are upgrading their phones on a less frequent basis. Cozza said smartphone life cycles have been extended to 2.5 years in mature markets, a trend she doesn't expect to change drastically over the next five years. Gartner cited a shift from two-year subsidized device programs from wireless carriers and updates that have become incremental rather than exponential as factors that have led to slower upgrade cycles.

That last bit is spot-on. Seriously, when was the last time we saw a truly groundbreaking smartphone, one that really knocked your socks off? There are plenty of excellent smartphones on the market but innovation has slowed considerably.

Looking ahead, Gartner says India has the highest growth potential as smartphones in the region have yet to overtake feature phones.