World-building is dependent on setting up consistent lore, and then respecting that lore with the stories in that world.  In single stories, that’s certainly of value, but over larger series it’s essential to keep people invested.

Why?  Value.  If the stuff you put out at the start is discarded, then it means it has little value and consumers can easily skip it.  It also instills a level of doubt that the current story will have no links to the world and reduce it’s impact.

Game of Thrones has some serious world building going on in the books.  Even the TV show did a very respectable job of maintaining that world.  The issues with the TV show don’t relate to lore with respect to the world, but in respect to the actions taken by the characters.  Like how you don’t set up a main villain for 6 years and then dispatch him in 1 episode.

Harry Potter had a consistent world up until book 7.  Then the play came out and decided time travel was a good way to impact the main storyline and alternate universes.  The JK decided that twitter was a great way to pad extra content to the original books and throw in some major curveballs.  Now, if you ignored everything that came after book 7, odds are you’re a happy camper.

In the comic book world, there are plenty of retcons.  In some sense this creates larger arcs across multiple volumes.  Superman has undergone multiple versions, depending on the needs of the writers and society as a whole.  Batman has had tons of versions.  The slight difference here is that when a retcon comes along, there’s usually some advanced notice and the break is clean.  Rarely do they every try to blend both stories and worlds together.

Playing through SWTOR brings more of this to mind.  While nearly all of it is considered “Legacy” now, it still bears mind that it’s consistent.  The stuff done in Chapter 1 is not negated by anything in Onslaught.  That there are so many intertwining storylines and that they rarely conflict is quite impressive.  Typically the storylines would branch/fork and then come back to a mainline resolution.  Onslaught is a bit different in that space, as the branches/forks are still present at this point.

This is in conflict with the recent Star Wars trilogy.  The Force Awakens was somewhat consistent, with a few interesting bits.  Finn’s battle with a lightsaber against a shock weapon was a bit odd.  The Last Jedi took a baby & bathwater approach, which kept the setting but ignored most of the lore from prior.  Apparently the Force can help you live in space, it can transmit you across the galaxy, lightspeed can be tracked and can be used as a weapon.  There are a few dozen more examples.  The problem with this isn’t so much that they break the existing lore, but that they negate all tension in the film.  The implications of each of those changes the entire galaxy.  Think of it this way – every Xwing is now a nuclear bomb, capable of taking out a capital ship.

I know there are a lot of people who are more interested in the individual story, and that’s ok.  I’m much more interested in the thought process of the world, and seeing how other stories could add to the base presented.  Wheel of Time had some amazing world building.  Sword of Truth was pretty solid.  Lord of the Rings was only written because a world was built beforehand.  When it works, it means the sum is greater than the parts.  When it doesn’t, you get something like the Terminator franchise, where you burn the audience so badly that even when you do get quality (Dark Fate) no one cares.

I’d like to say I’m hopeful that is not the case with Star Wars, but given Kathleen Kennedy’s comments that there is no source material to draw from… that raises some eyebrows.