The penalty is they lose their privilege to notify you because you turn it off, thereby losing out on your future revenue through marketing to you via notifications. Again, the question is why must Apple or Google do something each person can decide to do themselves?
Because some apps unfortunately are a necessity and we can't vote by removing them from our devices, but that doesn't mean we also decide to accept getting promotional notifications every hour on the hour from them because they take advantage of the fact that they're a necessity on our devices.
And why must Apple or Google do something? Well because I can't make the iPhone or Android so I cannot change the underlining code to make sure that the notifications I need (delivery notifications) aren't drowned out or not received because I don't want the "We used a bunch of machine learning to determine this thing that you don't want is something you may want, you should add it to your cart!" notifications.
"Eh just wholesale disable notifications" isn't always the best solution and the device manufacturer should be aware of that.
Yes Android has channels, iOS doesn't, but Android having channels doesn't mean that they are being used correctly.
A way to tell the manufacturer that an app is abusing their customers with notifications and allow them to take that ability away and enforce channels being properly used is a net good for everyone (except those who abuse it)
