I don't get Air either. My guess is that Air is just a stepping stone for a foldable iphone.
I can see a large unfolded phone being desirable if it had a stylus and I could use it like a small notebook, but just as a "watch Netflix bigger for $2000" device, no.
Especially if it has the worst camera of all of the phone models like the Air does.
Suspect this is a mindset thing if you mostly use 10 cent Bic pens you'll never care to make a habit of keeping them, and then when you're using an expensive gadget pen those habits carry over.
Even a pen that costs a few bucks (Signo UM-151 for instance) I know where they're at.