Since the question is specifically about what Apple could make developers do, I’ll say this: enforce the App Store guideline rule about not using push notifications for advertising.
I very rarely enable push notifications on apps anymore because so many use them for spammy advertisements. This makes apps less useful than they could be if notifications were used responsibly.
I keep thinking back to years ago when someone at work tried to tell me this guy was good and I could just tell on vibes alone to stay clear.