Apple iPhone 15 family of devices
iPhones are losing appeal in Apple's most important international market.
  • Apple entered a whole new hardware market this year with the launch of the Vision Pro.
  • But slipping sales in China show that Apple cannot get forget about the iPhone.
  • After years of iterative improvements, the world's most popular smartphone is in need of an upgrade.

The last thing Tim Cook needs this year is for the iPhone to give him a headache.

The Apple CEO already has plenty on his plate as he attempts to make a success of a fresh hardware push from Cupertino following the launch of the Vision Pro last month.