A notification management system sounds like something that needs to exist, but how would it work if companies don't adhere to standards? I don't see any way out of this that doesn't first involve legislation.
Technology moves really fast and laws move really slow. Hence i would prefer if we had a solution that would not require this kind of legislative intervention. But as you say a lot of applications will not play nice. And neither google nor apple really has the incentive to fix it on their side. Only an outside force could force this but i do not see how you would legislate this in a future proof way. And it would probably need to become a legislation adopted by multiple big companies before they would roll it out to all countries.
I would trust that about as much as I trust their spam filtering, which is very little. And notifications are usually a lot more important than any given email these days.
That's super weird to me because spam filtering works amazingly for me. I don't think I will buy an iPhone because of how well the machine learning based features on Android have been working on my pixel.
