The real answer here is to use the lightning -> 3.5mm adapter which comes with the iPhone, I believe.
Those who were around during the days of early 'home computers' - think Commodore bread boxes, Sinclair door stops etc - might remember the evolution from those devices which generally lived in a jungle of cords emenating from their sides and backs, connecting them to power supplies and peripherals to the more streamlined versions which came later - Commodore 128D, Amstrad all-in-ones, various species of MSX and yes, the original Apple Macintosh - which had most of the essentials built-in. Having one of those on your desk really separated you from the plebs who still lived in the jungle.
Apple seems to have forgotten that part of its heritage.
That is OK much of the time, but a faf is you want use your iDevice for music while working for some hours or while mobile for long enough that you might normally plug in a portable battery.
Unless they've started including the two function adaptor as standard but that will irritate people who don't want the extra bulk...
If you are someone who charges your phone while listening to music on a regular basis, then I can see the lack of headphone jack being an issue.
The real solution for that problem, in my opinion, is to just put two USB C or two lightning ports on the phone. They have much more usage than a 3.5mm port. Two places to charge from, charge and have external storage attached, etc.
If Apple was using USB C like they should be, then you could just plug them straight into that port.
But I cannot plug my headphones AND charge my phone.