The Atlantic on "Why" Stories Took Over your Smartphone:
Stories is not a technology, nor is it a feature. It is a media format, or even a genre, in the way that a magazine or a murder mystery or a 30-minute television program is. This is also why it’s a little silly to worry about who “copied” Stories from whom, since the whole point of formats and genres is to develop independent of single tools of creation and dissemination. The different styles of Story illustrate the form’s broad uses. On Snapchat, Stories are more informal, making use of the face-filters and geotags common to that platform. On Instagram, filters and Boomerangs and neon text and the like are more frequently used, as that platform’s heavily composed manner warrants.
And that’s also why “Story” is such a terrible name for this format. Contemporary culture’s obsession with storytelling runs so deep, everything has become framed as storytelling, even when it’s clearly not. Most Stories are not storytelling. They are sequenced, which is one of the definitions of narration: an account of events. But sequence is not sufficient to create narrative, and many Stories feel like random collections of unrelated materials. Most of the ones I see on Facebook and Instagram are one- or two-image sequences, hardly enough to play out a day-in-the-life, let alone a moment, anymore.
As the article points out, stories or storytelling are a very different kind of "story". I mean, that's what the name would and should suggest, but in the end the definition of what a story is has at its core a deep meaning that comes from the past, first by oral form and then through books.
The media might change but a collection of pictures or frames that are meant to disappear, in my opinion are far away to be defined like that.