The web is social
The inherent global discoverability, linkability, sharability of the web is what first made social networking social.
Apps made social more portable, and that is a great thing, but the easy ability to find and share content is what will always make the web the ideal social platform.
At first, the social web was all about friending and sharing cat videos, but the social web has grown up and is a daily part of our lives.
As highlighted on the Firefox Apps blog:
Mobile social media extends our reach and lets us engage with the world immediately, wherever we are—whether it’s keeping up with the news, booking somewhere to stay on vacation or listening to music.