Wireless charging has been around for more than a quarter of a century, but only over the past decade did smartphone manufacturers begin offering it natively in their handsets.
In 2012, Nokia was the first to adopt the Qi-based wireless charging in its Lumia 920 phone.
The Qi specification, the industry's most popular, allows for power transfer ranging from 5 watts to 15 watts in the latest v1.2 release. Apple chose 7.5W of power transfer for the new iPhone 8 and the upcoming iPhone X.
"Apple's been behind on this. Because they want to keep the device nice and thin, they didn't want to go with the crowd," said William Stofega, IDC's program director for mobile phones.