For example in the standard hero's journey structure there's a point called the "refusal of the call". This is where the hero, in his ordinary life rejects the call to go off on the adventure, but then fate or somesuch kicks his backside to actually go do Hero Things.
If you're talking about that "monomyth" thing, no it's not a standard hero's journey structure. It has elements of such, but it's very much not a standard's hero journey, it's more of "standard hero fanfiction story".
I didn't mention the monomyth. but the general stages are in pretty much every influential book on scriptwriting etc. The tropes are everywhere because all the major sources on storywriting were heavily influenced by Joseph Campbell. His seminal work came out in 1949. It's been heavily influential on modern cinema scriptwriting, and the concepts have spread to every medium from that. So, there's the idea that some tropes are fundamental and work in any setting/story, but there's also the historical fact that these theories have directly influenced the last 50 years worth of screenwriting, regardless of whether they're really "universal" or not.
The basic tropes are everywhere in published fiction not just "fanfiction". In fact I'd be highly skeptical if fanfiction commonly adheres to any sort of rigorous structure.
Some things really do happen in almost every story. Aside from the obvious "there is a hero" idea, you're most likely going to get some sidekicks, and a mentor character. And you can bank on the mentor either dying or being otherwise incapacitated sometime after the half-way point of the work, but before the Big Battle.
You have no idea how much of a
production line expensive commercial series are. They adhere to well established structures and theories of scriptwriting
far more than fanfiction does, because they have to when they're pouring 10's of millions of dollars into something they don't want to experiment with story structure on top of that. Look at Star Wars. That adheres to the monomyth almost to the letter. And Star Wars influenced a whole lot of other movies. The monomyth is a set of rules that professionals stick to because it always produces a workable story. It's not some fringe thing that crazy fanfiction writers are into.