The problem with push notifications
I am very picky when it comes to push notifications. My default setting is "off", and I will only allow an app to send me push notifications when it is truly important (Apple Wallet for example). A crucial criterion for me to keep notifications on is for the app to have consistent behavior and offer control over the notifications I receive.
For instance, I know for sure that Apple Wallet will send me a notification when it's actually necessary - a transaction that has occurred or when there is something wrong with my card. Not once did it happen that I received a promo notification from Apple Wallet; therefore, the notifications are still on.
For some reason, many other apps underestimate the cost of their users' attention and time. They consider it acceptable to send offers as push notifications and mix them with service notifications.
An example here would be Glovo which does not offer any control over notifications. Even though I want to know when the courier is close, I can't turn the notifications on because the app will send me promo ones whenever it desires.
Another example would be MAIB (web banking application). Even though they have the option to disable "Other notifications," I still get promos. This doesn't only mean that I can't receive notifications about transactions, but it also puts the security of my account under threat.
The right way to do it would be to separate the channels: have one for services and one for promos. Be consistent about it. If I uncheck the promo notifications and I get one in the service channel, it's a 100% chance I will opt out.
You could argue that everyone would opt out of promos if they were given a chance, and it's fair enough - people should be given a choice. If Glovo sends me a notification about a new restaurant, it won't mean anything to me - I will just get annoyed that I had to interrupt whatever I was doing to check the notification.
If you introduce a new feature in the app, show a changelog after the update or highlight a new feature when I open the app. The developers should take responsibility for the notifications they send and not be the "boy who cried wolf"