I know it's not perfect but it's good enough for most cases. It no longer makes sense to completely discount PWA when native apps have long suffered from app install friction. It's never going to beat typing a domain name vs going to play store, searching for app, clicking install, asks for overreaching permissions (why the fuck does a QR reader need access to my contact list), and after all your visitors drop off, the final nail is the loathed uninstall.

http://pwa.rocks have some pretty nice looking examples, and to most users, they wouldn't have a clue if it was native or not if they didn't see the Chrome Browser. But the add to home screen is the true killer app feature here, now your native apps are competing with Chrome Browser apps which is good enough for most use cases.

It's good enough when you can't afford to build native or your intended audience/product isn't primarily mobile, sure.

Just clicking through the samples at pwa.rocks - a good portion of these are demos/prototypes. Some are just well designed responsive websites that aren't much else than a brochure/ecommerce sites. Sure, it's not hard to format content for mobile and make it look nice. There's a couple of good ones on this list, but for the most part I wouldn't put this list against a list of top ten well designed native apps. They're just not comparable.

That said, I'm not arguing against building out nice mobile responsive sites (and this is something that I think gets forgotten way too much with "rich interface" single-page app designs that are all the craze on desktop). I'm a strong believer that every site should be written with mobile in mind first unless there are strong use cases to argue against it. Don't ever force your users to install an app to consume your product unless the product itself is the app.

Not sure if you have any experience, but Cordova and Xamarin are not the same kind of thing. In Xamarin you (and I would recommend that in most cases) get to use the native APIs of your platform of choice. Aka when targetting iOS you will be using UIView and when Android View. And all methods on those objects are the same ones you would use in Swift and Objective C for iOS and in Java for Android but then under a thin wrapper of C# or F#. Cordova is very much not that. I am not sure where the confusion under devs comes from but Xamarin generally is not used to run the same GUI codebase on two platforms like one would do with Cordova.