CES used to be the biggest tech event of the year. Every January, almost 5,000 companies and 180,000 people descended on Las Vegas, for the biggest industry trade show in the world. Every electronics company you've ever heard of is there, along with thousands of others that you haven't. Except for Apple, and that matters a lot.
As tech products like smartphones became more and more ubiquitous, products that were unveiled at CES would all overshadow one another, leading to less headlines and coverage for each new product. A new Android phone might be universally praised, but that didn't matter if a rival introduced theirs on the next day.
Just look at OnePlus. This past fall they had planned to unveil the new OnePlus 6T on October 30th, but when Apple announced the 2018 iPad event for the same day, OnePlus rescheduled their event to a day earlier. OnePlus CEO Pete Lau even acknowledged the problem on the company's message boards.
Lack of innovation?