I agree that it seemingly shouldn’t matter to them, but they clearly care about it. If it’s a slide on a presentation, it’s because they care about it, or care about presenting it.I don't see it. It's a slide on a keynote, sure, but it could just as easily be about how many retail stores they opened or how much carbon offsets they purchased. They will brag about any number that benefits them. They don't get any revenue from people updating their OS. If you want to stay on 18 or 17 or 12, fine. It doesn't cost them anything. They are already focused on 27 at this point. They just might need a different slide for this year's keynotes. Maybe one on how many more Siri queries people did with the new LLM Siri.
It’s a free product seemingly, so the fact they report the number is what shows they care, since there’s no revenue growth directly correlated.
But then when you think deeper it makes sense they care about it, since Apple’s entire foundation is vertical integration with hardware and software, combined with maintaining control of the software experience.