It is nonetheless interesting that Google have killed this off some time before a complete replacement is ready. It reminds me (to a slightly reduced extent) of how Google Gears was killed off completely before an alternative for its offline support existed—it was four years before service workers fixed that. Still, removing such things early has helped people adopt the standardised form rather than continuing with a Google-specific thing, so as a Firefox proponent I’m glad they did it this way each time, however little sense it seems to make from Google’s and the user’s perspective (seriously, they actively removed offline support from Gmail—and they still haven’t reintroduced it).