But couldn’t this previously have happened with a Qualcomm modem as well?
You can always easily tether to your iPhone. It’s hard to imagine people who own a Mac but don’t have a phone — I assume Android can also provide tethering? Aside from the BOM price increase and physical real estate, do want to pay $10/mo or whatever for an additional line?
It could have, but my understanding is that Qualcomm's contracting is pretty brutal. They had no choice but to accept those terms with the iPhone. With the Mac, so long as they were selling without the modem, why bother?
I own a MacBook Pro and an iPhone (and other Apple devices which have cellular modems in them: an iPad and an Apple Watch). The tethering is flaky and burns two batteries at once while adding latency. I want an always on Internet connection like I can get with a Dell laptop.
The Qualcomm royalty agreement has been the problem, as they reportedly get a fraction of total device cost.
How my cellular provider bills me for it is irrelevant.