That's missing the point of what makes a good app. It like you say about Cordova apps: the last 20% takes 80% of the time.
Notifications are completely different on iOS and Android. Sharing data between apps is completely different. Wearables are different. Communicating with a server is different. Accessing contacts is different, as is accessing the camera. Sensors are different, and often differ between Android models.
Most of the big mobile success stories we've seen in the past 5 years have come from people utilizing the unique features of the phone, not treating it like a 5-inch dumb terminal.
Notifications are completely different on iOS and Android. Sharing data between apps is completely different. Wearables are different. Communicating with a server is different. Accessing contacts is different, as is accessing the camera. Sensors are different, and often differ between Android models.
Most of the big mobile success stories we've seen in the past 5 years have come from people utilizing the unique features of the phone, not treating it like a 5-inch dumb terminal.