Even if we sideload an app, with modern mobile OS architecture many classes of apps will be almost useless if sideloaded apps will not be able to use push notifications provided by an operating system.
Currently you have 2 ways of providing this to your users: run the app in the background, maintaining a persistent connection to the server, or via push notifications, where an app is woken from disabled state and displays a message. And background processes are killed off on iOS in less than 15 seconds (the documentation states 30 seconds, but we've never seen it in practice). That leaves push notifications the only choice.
Of course, worst of both is interruption notifications where you see part of the message, tap to read the whole thing and then get to wait for the thing to load.
I have disallowed notifications for almost all apps on my iPhone. I will check an app when I want to check it, not when the app developer wants me to.
Conversely, it will also be great for any possible sideloaded app to also have the system give the user that same choice.
Now if one side starts to impose their choices on the other is when we start having a problem.
Do you want WhatsApp to deliver a message to you from your mom or special one that they urgently need help? Or should they wait till you will want to check the app?
Not sure how much it would help. My family is at least an hour away and I might not see the notification anyway.
That is a far cry from permitting it for all apps though.
It is frankly shocking to me how many people fail to understand that.
"I don't like push notifications, it means nobody needs them"
It is actually shocking to me that some people have this extremely narrow view of this problem. There are huge classes of applications that absolutely require immediate notification of the user, but here people just handwaive this as a non-issue because "I don't like to be disturbed".
How about a doctor called for an operation? Your car being robbed? Incoming bank payment? New ride request for a taxi driver? Disaster notification? VoIP call? A soccer game beginning? Billions of uses you just discard because you don't want it. Gross.
You can make up all sorts of notifications for emergencies but I could counter with what happens if I am in the shower when I get the notification? I don't want a tornado warning the last possible second, I want to know it ahead of time so that I can get to a safe place. If my car is broken into there is nothing I can do, if my grandmother has a fall it is at least 30 minutes before I can get to her, I don't need notifications for bank payments (it gets added to a list that I renew when necessary).
I wouldn't want a notification for an active shooter at all -- if I was hiding from the shooter, it could give my location away.
The idea that apps just get to notify me whenever they want is insane. This is especially true in games.
Heck theses days a website gets to buck me about it just by me visiting it.