Why doesn’t Safari outside of MacOS allow notifications

The whole Apple antitrust talk has got me thinking about something else and that is about Safari Notifications.
At WWDC 2013 which is almost 7 years ago as I write this a feature was released for OSX Mavericks which allowed you to program notifications into websites, a useful feature that unfortunately some sites use instead of RSS feeds and little allow customisation.
Even though this feature was released 7 years ago it has yet to be released on iOS or iPadOS 6 or maybe 7 years later.
When the iPhone was released Steve Jobs notes that applications can be written in HTML 5 and JavaScript noting there wasn’t really a need for an App Store but this changed very early on, but it has got me thinking if the service revenue for the App Store has come into consideration when it comes to not having mobile Safari notifications.

it would solve the problem with certain apps being refused from the App Store, they could be written as progressive web apps and use Safari notifications to let you know when you have an email, in fact most functions could be done in Safari with the advent of Web Assembly Apple has an opportunity this WWDC to enhance this or will it go 8 years without this functionality?