Continuity is an important piece in storytelling. If events don’t line up well enough, it can be a source of confusion or annoyance for potential viewers. But the longer a series might go on, the harder it is to maintain said continuity continuously.
Not that writers are going to stop trying. Even when they should.
Once a franchise has gone on long enough, with enough writers putting their pen to the universe or its characters, it can be hard to keep everything straight. At that point, the mere effort of trying can be debilitating. Eventually, the objective of a story stops being to create a compelling narrative and becomes about fitting it into the canon.
Sci-fi is particularly guilty of this issue. Just look at all those spin-off shows for Star Wars, like Obi-Wan. We can’t have a stand-alone Obi-Wan adventure; we’ve gotta find a way to fit it into the story of the main movies without contradicting the prequels or the originals. Because of this, the show becomes limited by the need to remain faithful, essentially putting shackles around the writer’s wrists.
There’s also the fact that the show itself wasn’t a great idea, but that’s beside the point.
Don’t even get me started on shows like Star Trek or Doctor Who. The latter is a time travel show and the former is a show that occasionally employs time travel. Both are a recipe for continuity nightmares. If anyone tries to explain to you how each Star Trek show connects to each other beyond the time gaps between them, get the hell out of that conversation immediately. Especially if they mention any show made past 2010.
Certain stories even seem to glorify their adherence to continuity. Going back to Star Wars, just look at Rogue One. That movie ends right where the original movie began, as if to say, “See? It fits right in there! Aren’t we so clever and cool?” like a kid bragging about doing something their friends said they couldn’t do.
Now, good continuity can be a rewarding experience when it’s done cleverly. One Piece rewards eagle-eyed readers with its clever little details that pay off several years later. That works well because it isn’t a hindrance to the story; it’s either a pay-off to a long mystery or a clever detail to reward die-hard fans. You could miss it entirely and it wouldn’t matter.
Even then, the continuity in that series isn’t perfect. But don’t let the One Piece fandom find out I said that. They’d either kick me out or crucify me.
There comes a certain point where you just need to abandon the notion of continuity and focus on the story. Who cares if the Obi-Wan show contradicts another movie or if a Star Trek show fits into the timeline; if it’s a fun story, people won’t care. People might point out some of the inconsistencies, but that’s about as inconsequential as someone pointing out a zit on a pubescent teenager’s face.
If it’s a short, singular story, then yes. Continuity is important. But once your franchise has gotten big and long enough (inappropriate joke here), then sometimes the best thing you can do is just say screw it. Who cares if the latest entry fits into canon? Just make a good story, canon continuity be damned.
Or just start parodying yourself. Sure, that’s the sure sign of any dying media franchise. But if you’ve gotten too big for anything at all to make sense, why not have some fun with it?