Presumably servicing wired headphones, but agree it's an odd choice to not also include one in the back— particularly when unlike a laptop there's no built in speakers, and Apple has been pushing hard on bluetooth audio since the iPhone 8 in 2017.
Oh that's right yeah— 6/7/8 all had the same form factor as that was the time that the off-year S versions were also dropped, so I always get confused.
And to further muddy the waters, the space in the 7 chassis for the jack was mostly still available, which led to that one madlad bodging in his own headphone jack, for a one of a kind iPhone 7:
The 6 actually had an S release, as well as the X.
But yeah the headphone jack dropping was obviously just to get more people onboard with AirPods that launched at the same time. And you can't say it didn't work! I remember when the first images of people wearing AirPods came out and it was the laughing stock of the internet. People said it looked like you had Q-tips hanging out of your ears, or the tips of an electric toothbrush.
A few years later and they're pulling in tens of billions of dollars per year, just on AirPods sales alone. AirPods could be pulled out into its own business and it would be seen as a wildly successful tech company.
