giving users complete fine-grained control over notifications and level of severity by app

Android does exactly this, I can go into any app and it’ll give me a breakdown of all the types of notification it sends. So like Instagram will have DMs, friends posts, “What’s new” etc. As separate notification types and I can go into each and determine if it’s super critical and should override even DnD all the way down to completely disabled. It even tells you the average notifications you get for each type.

It’s not perfect, it depends on the app dev for proper breakout of the types. I’ve seen some apps that dumps all notifications into the same channel, but all the major ones are pretty good about it.