“Apple's iOS has some limitations when it comes to push notifications. For example, iOS devices do not support background sync, which means that PWA push notifications cannot be delivered to the device when the user is not actively using the app. Additionally, iOS devices do not support silent push notifications, which means that notifications cannot be delivered to the device without the user's knowledge.
Another limitation of iOS devices is that PWA push notifications cannot be delivered to the lock screen. Instead, they are delivered to the notification center, which can be accessed by swiping down from the top of the screen. This means that users may see the notification later, which could result in missed messages.”
Apple will maliciously comply until people give up.