It’s a comedy trope. Seinfeld is probably most famous for the formula with back-references throughout the series. Arrested Development dabbled in it, and Community took it to the extreme of whole story arcs. Brooklyn 99 and New Girl revel in it. A less comedy-specific example, Buffy, created a role for the throw away character (Spike) because he was so well received, then went on to do several more episodes along a similar theme (Zeppo, the one about Jonathan being a superhero, the musical, come to mind).

Movies are less susceptible to being described as formulaic, but an iconic movie, The Big Lebowski, could reasonably be summarized this way (albeit the series is serialized into one piece). Coffee and Cigarettes doesn’t satisfy the “nobodies” in the literal sense, but it’s almost entirely this formula.

I’m just citing examples I can think of, I haven’t watched most of what people have watched. And I don’t mean in any way to dismiss the actual work, or the concept, or your finding novelty in it. It’s a really cool device for storytelling, but it’s definitely not a unique device.