There are apps that need 100% notification delivery reliability (in a sense that OS or delivery server itself will not be allowed to decide to just drop PN for policy reasons). I guess Google can only "solve" this (by simply not passing them through any "classification") for their own apps only?

For some android phone brands delivery reliability is like 40-50%. Some brands are better (reaching 80%, still bad) some very bad (usually the chinese brands, for some reason).

And the user has no say in this. They can't say: deliver every notification without classification. Or "allow this app to wakeup whenever it wants". Everything is babysat by the great overseer, even if you write the app yourself for yourself.

Have fun writing a telephony app that receives only 50% of calls. :D