Apple is expected to drop its proprietary Lightning port with the release of the iPhone 15 in 2023.
The switch to a USB-C port has been predicted by well-known Apple analyst Ming-Chi Kuo in a couple of tweets. Kuo believes the iPhone released in the second half of 2023 will be the first to make the switch, and based on Apple's regular release schedule that will be the iPhone 15.
As to why Apple is finally giving in and dropping its proprietary port, Kuo believes the company is realizing there's some advantages to USB-C, notably data transfer and charging speed improvements. How much of an improvement will come down to the final design of the 2023 handset and what support is integrated into iOS in time for the launch.
Kuo also believes USB-C will increasingly become the focus for "USB-C-related suppliers of Apple's ecosystem" as they prepare for the switch. Not only will it mean a whole new range of USB-C accessories being required for the launch of iPhone 15, but also supporting anyone with existing iPhone accessories who wants to keep using them with the new iPhone models.
As usual, Apple never comments on rumor and speculation, but the past few years have seen many of the rumors around what the company is planning turn out to be true. iPhone owners are sure to be split on whether the switch to USB-C is a good idea or not, but at least it would prevent Apple having to fight the European Commission.