Earlier quoted context omitted.
Which features? getUserMedia is now supported in WebViews, so one can build, for instance, a FaceTime competitor that runs on Chrome on iOS, where it wasn't possible a few months ago. But the Fullscreen API still isn't supported, a blow to the web-based FT competitor. What else?
Push notifications are impossible on iOS PWAs. Basically takes out a big chunk of possible apps you could build on this, no one wants e.g. a messenger that can't notify you when you get a message.
I deliberately disable push notifications in all messengers to avoids distractions, even though I'm actively using the messengers _when_ I want to sync with people.