Not just that
It is also all the 14nm modem chips they are supplying to Apple - over 200 million a year now that they are used across the whole line including older iPhones they still sell.
Back when they inked their agreements with Apple I'm sure they assumed they'd be on 10nm long before this became an issue. When they remained stuck on 14nm, supplying 200 million chips to someone else (and Apple's contract not allowing them to say "sorry, there's a shortage, you'll have to take less than you need") was a major reason for the shortage.
Just look at the times when Intel said there was a shortage - right when Apple went to 100% Intel modem chips instead of an Intel/Qualcomm split. Look at the times when Intel said the shortage was easing up - in early part of a year, when Apple's seasonal sales fall off and they need fewer modem chips. Then when summer hits the shortage does again because they are ramping modem chip production for a new iPhone launch. It has been like clockwork, and exactly matches Apple's demand.