What just happened? It's safe to say that smartwatches aren't the fad some people thought they would be. In fact, the most popular of these devices---the Apple Watch---sold more units in 2019 than the entire Swiss watch industry.

Apple doesn't report official sales figures for the Apple Watch, so Strategy Analytics collates data from retail partners and vendors to come up with estimates. It states that the wearable shipped 31 million units worldwide in 2019, 10 million more than all combined Swiss watch brands, which include Swatch, Tissot, and Tag Heuer.

It's estimated that the Apple Watch saw 36 percent growth last year compared to 2018 when 22.5 million units were shipped. The Swiss watch industry, by contrast, declined 13 percent in 2019, falling from 24.2 million to 21.1 million.

Neil Mawston, executive director at Strategy Analytics, writes that while analog wristwatches remain popular among older consumers, younger buyers prefer smartwatches.

Some Swiss watch brands have entered the smartwatch market, most notably Tag Heuer with its Connected and Connected Modular 41, and Montblanc with its Summit 2, but they're all double or treble the price of the Apple Watch, and can't match the device when it comes to software and features.

Things have come a long way since 2017 when just 14 percent of executives in the Swiss watch industry considered smartwatches to be a threat to sales, while 72 said they'd have no effect at all. The remaining 14 percent saw the wearables as an opportunity.

Last month, a study from the Pew Research Center showed that around one in five (21 percent) of Americans now regularly wear a smartwatch or fitness tracker.