There's one major reason to care - the AppStore has a threshold (200MB i think) over which it will warn users about the app's size if they are on cellular connection (IIRC it used to block downloads entirely). So there's a fair bit of incentive to stay under 200MB.
If they're on mobile. But then we are talking about people with $1000 phones, who almost certainly have tens-of-gigs-if-not-unlimited data plans anyway, so companies still don't care.
