The iPhone 16 series got a relatively glowing review from teardown and repair group iFixit thanks to its new debond-on-demand batteries.
However, iFixit did also note that Apple's 'new' Camera Control button complicates things somewhat. Unlike most iPhone parts, the new capacitive key is welded to the inside of the frame at 2 points: it seems to have its own dedicated integrated circuit for its new functions (which, unfortunately, do not include Touch ID).
Phone Repair Guru also found that swapping parts between 2 iPhones with the goal of simulating a Camera Control replacement results in the designation of the entire enclosure of the iPhone as a replacement part in iOS 18's new Parts and Service History section.
Moreover, Apple does not sell the Camera Control as a replacement part - but does stock iPhone 16-series enclosures, thereby implying that a user might indeed have to buy a whole new mid-frame for their device should the button break.
Just as well it's covered in sapphire crystal - however, it is an indifferent grade of the material that can register at a level 5, 6 and 7 as well as 8 as might be expected on the Mohs hardness scale, as reported by notorious device durability vlogger JerryRigEverything.
Accordingly, as recently noted by another online contributor Hugh Jeffreys, the iPhone 16's new independent repair-friendly upgrades might not be all they are cracked up to be, particularly as they are still at the mercy of Apple and its servers in order to work as intended.