I think the differentiating factor here is Chrome's push to support and utilize the Service Worker API (https://developer.mozilla.org/en-US/docs/Web/API/Service

I think the differentiating factor here is Chrome's push to support and utilize the Service Worker API (https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API https://developer.mozilla.org/en-US/docs/Web/API/Service_Wor...). The opportunity for web apps to have an offline experience and utilize push notifications is not only exciting but game changing for the web platform as a whole.