TL;DR - As of Feb 2017, Progressive Web Apps are a sufficiently powerful platform that Twitter has moved all of their mobile web traffic to a React PWA.

As of August 2016, Progressive Web Apps actually offer more hardware access than commonly thought. Here's a screenshot of whatwebcando.today from my Chrome 52 stable on Android:

Hardware access includes

• geolocation - supported in the vast majority of browsers
• camera and microphone via the getUserMedia/Stream and the upcoming MediaStream Image Capture APIs
• device vibration
• screen orientation and accelerometer access, including compass and gyroscope
• battery status

Upcoming hardware access

These features are being implemented or already work in some browsers:

• Bluetooth via Web Bluetooth API
• NFC
• ambient light sensor (works in Firefox 48+)
• proximity sensor (works in Firefox 48+)
• accelerometer, magnetometer and gyroscope sensor access
• shape detection API

Another important point to note is that the Origin Trials Framework (implemented in Chrome) enables manufacturers to expose and test hardware (or software) capabilities without having to go through the standardization process. For example, a phone maker could expose an API for reading the values of a pressure sensor, refine it, then submit it for consideration to the W3C.

Besides hardware access, there are also software features traditionally employed by native apps that are now available to web apps.

Traditionally native features that PWAs can also use

• push notifications
• working offline
• adding an icon to the home screen
• appearing in the apps list thanks to WebAPKs - Progressive Web Apps can now be packaged into actual installable Android packages!
• launching in full-screen
• clipboard access

• hardware-accelerated 2D/3D graphics via HTML5 Canvas or WebGL - check some of the HTML5 Canvas demos, WebGL sites or the three.js library. A 2014 benchmark of the Unity cross-platform game engine compared native vs. WebGL rendering performance, and concluded that

  "The most important takeaway is, while there are still areas where WebGL is significantly slower than native code, overall you can get expect very decent performance already, and this can only get better in the future."

  The gap has indeed been closing.

• reading user-selected files in any browser
• slick, smooth UIs with 60fps animations

These features cover a lot of use cases, and many popular native apps nowadays could be rewritten as PWAs. Take Slack, for example. Its open source alternative, Rocket.Chat, is building a PWA version. For more PWA demos, see https://pwa.rocks.

Native-like features coming to PWAs

• handling intents  —  for example, sharing a page to another app, or being the share target, e.g. a PWA chat app that receives an image to set as the user’s avatar

Native Android features that PWAs currently lack

• contacts, calendar and browser bookmarks access (lack of access to these could be viewed as a feature by privacy-conscious users)
• alarms
• telephony features - intercept SMSes or calls, send SMS/MMS, get the user's phone number, read voice mail, make phone calls without the Dialer dialog
• low-level access to some hardware features and sensors: flashlight, atmospheric pressure sensor
• system access: task management, modifying system settings, logs

Progressive Web Apps offer features that native apps lack

• discoverability - content in progressive web apps can easily be found by search engines but a content-centric native app like *** won't show among app store search results for content that it does offer access to, such as "pwa vs. native". This is a problem for communities like Reddit, which can't expose their numerous sub-communities to the app store as individual "apps".
• linkability - any page/screen can have a direct link, which can be shared easily
• bookmarkability - save that link to access an app's view directly
• always fresh - no need to go through the app stores to push updates
• universal access - not subject by app stores sometimes arbitrary policies or (unintended) geographic restrictions
• large data savings, extremely important in emerging markets with expensive and/or slow Internet access. For example, e-commerce website Konga cut data usage by 92% for the first load by migrating to a PWA.
• low friction of distribution - if your progressive web app is online, it's already accessible for Android (and other mobile) users.
  • 65.5% of US smartphone users don't download any new apps each month
  • PWAs eliminate the need to go to the app store, search for the app, click Install, wait for the download, then open the app. Each of these steps loses 20% of the potential users.