Push notifications are good for messaging apps (including chat support, etc.). They're 100% opt-in and harmless.
Web Share is barely a thing. It's literally just a call to an already existing browser function and deprecates all the vendor-specific embeds in most sites (each FB, Twitter, etc. share button you see either uses this single-function API, or loads their huge blob of JavaScript on every page that has it - which do you prefer?).
As a user of Web messaging apps, I also like the Visibility API, because it allows the apps I use to stop rendering while in background and just queue up messages to render when I look at them. This allows the process running those tabs to basically go to sleep (even swapping sometimes) which increases battery life and performance.
The rest of the ones you listed, I agree, really shouldn't be in Web browsers.
Web Share is barely a thing. It's literally just a call to an already existing browser function and deprecates all the vendor-specific embeds in most sites (each FB, Twitter, etc. share button you see either uses this single-function API, or loads their huge blob of JavaScript on every page that has it - which do you prefer?).
As a user of Web messaging apps, I also like the Visibility API, because it allows the apps I use to stop rendering while in background and just queue up messages to render when I look at them. This allows the process running those tabs to basically go to sleep (even swapping sometimes) which increases battery life and performance.
The rest of the ones you listed, I agree, really shouldn't be in Web browsers.