Yeah, this is why devs and designers cannot be trusted to manage notifications on Android, iOS or any platform. Shit will instantly be abused to drive (users insane) "engagement" and all kinds of mental gymnastics will be done to justify the dark pattern as something positive.
I hear you. The documentary The Social Dilemma pointed this out so well. There needs to be centralized management and many big companies are trying to build large teams to manage all the craziness. I think having detailed user preferences and using machine learning to understand if the notification even needs to be sent are a few things that stick out that I've seen some engineering programs focus on. Here is a description of what LinekdIn started doing a few years ago.
Aren't there some cases where they could be valuable? like alert that plane is delayed before you leave for airport or that your uber has arrived outside?
Yes, as I acknowledged in my comment. But notifications have been so widely abused as to reduce their utility for cases where they would have been useful.
For me, the notification bridge has already been burnt to the ground, though. There is every reason to expect that allowing any application to do notifications will result in garbage ones as well as useful ones.