The "notch" design, once heavily criticized, is now becoming a trend on high-end smartphones.

According toCNETIn the fourth quarter of 2017, the smartphone business witnessed its first year-on-year decline, leading observers to believe the market had passed its golden age. In reality, today's consumers are less enthusiastic about owning a new smartphone, as newer models often have only minor design changes compared to their predecessors, and the specifications and features are only slightly upgraded.

However, things started to change in the first quarter of 2018. Research firm Gartner recently predicted that total smartphone sales would increase slightly by 1.6% this year and reach 5% next year. The company also suggests that by 2020, when artificial intelligence is relatively mature, smartphones will spark new demand for users.

While smartphones have changed very little over the years, Apple took a new step by adding the notch to the iPhone X. Loved or hated, this design has been copied by numerous competitors. Huawei and Asus have already released phones with a notch, while LG and OnePlus are rumored to be following suit.

The notch on the iPhone X, originally designed to house sensors and cameras at the top of the screen, now seems to have become a hallmark of a premium smartphone. And users are starting to see more and more smartphone models with a notch.

According to market research firm Gartner, users today spend more time using smartphones, especially high-end devices. Therefore, the "notch" design seems likely to become more common in the near future.