As a user, so many of these I wish did NOT exist. E.g: Push Notifications, Banners, Web Share, Contacts, Page Visibility, Badging. Uncertain about USB, Bluetooth, Locks, Keyboard Lock, and Native File System. I don't want my browser doing those things.
On the other hand, the web as a runtime is one of the most universal platforms we have. If I run Slack in a browser, I sure do want it to be able to notify me! (Though I wish doing so felt more like the Electron app - I’d rather use my browser than Electron if the UX were similar enough. I already have a browser, I don’t need another per application!)
And as an occasional user of less popular mobile platforms (Ubuntu Touch, etc) a more featureful web runtime helps close the gap between those platforms and Android/iOS.
I do think it’d be better if these two use cases were more explicitly distinct than they are now, though.