Joke? Push notifications have a lot of valid use cases for web apps even if they are useless (or harmful) for web pages. The platform is shared between the two categories.
Push notifications are cancer. Push notifications are used a hundred times more for spam than they are some above board legitimate purpose. Even legitimate users have marketing departments foaming at the mouth to push ads with them.
More importantly, can it aggressively fingerprint them and supply adtech companies with an approximation of their identity?