Some of the functionality listed on this site is not part of the web platform, but rather Blink-only APIs Google implemented unilaterally that have been explicitly rejected by Mozilla and Apple.
Mozilla rejects stuff like webusb while apple is blocking add to home screen, push notifications, etc. Stuff that is needed to replace many app store apps.
Firefox supports both add to home screen and push notifications.
PWAs already support push notifications and add to home screen on iOS.
Or by “add to home screen”, are you specifically referring to BeforeInstallPromptEvent / prompt()? That isn’t a web standard. It’s something Google alone have implemented, it’s a Chrome-only feature. Firefox hasn’t implemented it either.
> Status of This Document
> This specification was published by the Web Platform Incubator Community Group. It is not a W3C Standard nor is it on the W3C Standards Track.
If its that simple then why is Apple blocking the most useful features like push notifications and add to home screen? Those aren't particularly useful for tracking.