But the full "scope" is not necesarily the story the product is telling (nor you need to know it).
I.e: the full "scope" story of Star Wars (1977) is the conflict between Jedi vs Sith and the balance of the force through many decades/centuries but, the actual story of Star Wars is about a young farmer from a dessert planet joining a rebellion againts an Evil Empire.
I'd say it's more of an inversion of "show, don't tell". The information/scenes are there, just utilized in another format. It's more and more common these days with "cinematic universes" and long-running franchises that have "scope creep", where the nature of the franchise changes as more and more works are released for it.
It's funny that you say that the "actual story" of Star Wars is just about Luke Skywalker. It's not. Not anymore. By Lucasfilm's own admission and their most recent handful of DVD releases, the "Star Wars/Skywalker Saga" is largely about the fall and redemption of Anakin Skywalker.
The context of A New Hope (later renamed Episode IV: A New Hope) in 1977 was that of a young farmboy who joins the rebellion against the Empire. In the context of 30-plus years of changing authorial intent on the part of George Lucas, along with the existence of the prequels and rest of the OT films, the film franchise is now largely characterized by both the production studio that created it and the fanbase as one six-film long saga about a character who fell from grace and was redeemed. He's become the series mascot, had extra scenes shot for
Rogue One to give him a few extra moments of screentime, occupies the front cover of the "Skywalker Saga" boxset and has been reframed as the lead character. Fans of the franchise are generally steered towards boxsets that reframe Luke's story as part of a larger narrative that is dwelling on another character, with A New Hope itself being reframed as only a small part of this story of Anakin.
And that's not counting the myriad number of EU works that have nothing to do with either the Jedi or Sith (i.e. Rogue Squadron, the Ewok films, Droids, the Star Wars Marvel comic run, et al.) that focus on lesser-known aspects of the universe.
This is a long-winded way of saying that SW has scope creep that's caused it to run far beyond its original intended goal, and in many cases, requires you to view additional media to better understand the overarching story.
XV doesn't really go that far in terms of scope drift (as Wol mentioned above), but it still gets plenty of this -- they planned an entire multimedia experience around the game.
Don't believe me?
The only way to fully understand the events in
Final Fantasy XV is to view some of the tie-in media, which was noticed and pointed out in many reviews published during the game's launch.
- The Platinum Demo of the game is actually a standalone tale that is being recounted by Noctis to his friends, and details an experience years before where he has to travel through a fragmented dreamscape with the help of his guide, Carbuncle. This demo was officially canonized in the Brotherhood anime (see below).
- A King's Tale is a standalone game that was originally released as a Pre-Order Bonus for ordering through Gamestop or EB Games, and recounts a tale that takes place 30 years prior to the start of the main game.
- Prologue: Parting Ways follows Noctis and his friends' activities just prior to the start of the main game. It was previously released as an audio drama in Japan, but was later converted into an e-book and released as a free download.
- The short film Omen was originally released during the 2016 Paris Games Week, and follows King Regis as he has a premonition about his son and asks the Crystal of Insomnia which course of action he should take.
- Kingsglaive is an anime prequel that takes place during the events of the game's first chapter. Not only does this anime explain and show events that are only referenced during the game (notably, the death of King Regis himself), but it also utilizes footage and ideas that were originally planned for its early Versus XIII incarnation.
- Brotherhood is a six-part anime series which was released on Square-Enix's Youtube channel, and chronicles the backstory of Noctis and his companions.
and because with just hints of info in the Deus Ex saga is more than enough for me. But yeah, I get that people want to know more about stuff (heh, don't I know it? Only this franchises haven't scratched that point for me) and it's a dick move to include interesting info in other pieces of media.
