Before you could just turn off an app's notification sounds and vibration through its notification settings.
But now with the introduction of notification categories this has become an incredible amount of work. For example the Facebook app has something like 30 categories. Do I have to go into each and every single one individually to turn off vibration and sound? That seems like a really horrible way to go.
I also don't want to put my phone in silent mode because I want to hear it when I get a phone call.