Well they don't call it polyfills but they implement e.g. Promise in their own way. And I've used it in the past so to get rid of jquery I would have to rewrite

Well they don't call it polyfills but they implement e.g. Promise in their own way. And I've used it in the past so to get rid of jquery I would have to rewrite that code to use the native one now. For approx. 0 benefit to the end user.