Why collaborative storytelling is a meaningless phrase

[Cazero]

So what if they're "commentating" a fictional sports match in real time? A match that only "exists" in that they are imagining it and describing it to each other?

By this definition, since nobody is "watching the match" (or experiencing the game world), that makes them clearly storytellers, no?

The players are litteraly making it from nothing. You can't have a more involved interaction than that. The story having no physical existence is only making that point stronger : the definition of events is the experience.

To put it another way: Does the Welcome to Nightvale podcast "tell a story"? Or is it merely a fictional radio show, factually describing events as they happen, in a way that is somehow not a story?

There is a huge additional distanciation in that example unless you remove the audience from the equation. And for some reason I doubt people make podcast just to listen to themselves talk.