This isn’t entirely true because most apps use a WebView to keep users inside the app — instead of opening a native ‘browser’. Look at the most widely used apps where much of time spent, is inside the WebView — Facebook, Messenger, LinkedIn, Twitter et al and now services like HipChat and Slack open links inside the WebView. In fact, I see them going in the direction of auto fetching the content for a richer experience — without even bringing users to the webpage. All inside the app.
This is why I’d like to see Mozilla continue its awesome work in the browser world (I never agreed with the OS initiative) and extend this to creating a new WebView — or help extend what’s there so it’s richer, more privacy-aware and more secure. Most WebViews used today don’t even display the URL so it’s impossible to tell the difference between a legit site and a phishing site.