There are some bad apps which will abuse it and use only one category for the important things and ads. But mostly - it's ok. Enforcing a channel for ads would be even better.
Yeah this works really well on Android, I'm surprised Apple hasn't taken a similar approach.
You don't want ads from Uber but still want a push when your ride arrives? Just block the ads channel in settings.
As you said I'm sure there's some bad apps out there that only have one channel, but I haven't noticed any. The big apps seem to support this quite well.
Don't enforce things if on average they already work. You don't know the second order effects. Currently developers have to balance spamminess versus people opting out completely, which probably diminishes future use of the app. That's a nice informal balance. Formalizing it may lead to much more spamminess since hey, you can always opt out.
You don't want ads from Uber but still want a push when your ride arrives? Just block the ads channel in settings.
As you said I'm sure there's some bad apps out there that only have one channel, but I haven't noticed any. The big apps seem to support this quite well.