Why?
it is designed to let web apps and sites determine whether a corresponding native app is installed on a user's device.
The purpose of the API ... to distinguish between the ...two sets of notifications
If users are using the app, then they are very unlikely to opening the webpage version at the same time. And even when they do, the webpages often point them to their app. In additional to the privacy issue and the fact it only works on android, this feature is pretty pointless right from the start.
Biting the hand that feeds IT
