The Star Wars movies are known for following the "hero's journey" template for storytelling, wherein the titular hero goes on an adventure or quest, wins whatever fight or conflict they are up against, and returns home changed or transformed in some way. It's an effective method for telling a coherent story, but it can feel a bit repetitive and bland if it's overdone. Even with the framework aside, a story or franchise can start to feel repetitive when the same character archetypes are used over and over again.
Star Wars is definitely guilty of this. All three main trilogies, as well as the spinoff movies, seem to have different versions of the same character in every series. The original trilogy can get away with this, because they were the first to do it and to introduce these character types to the Star Wars universe. However, the writing starts to feel a little lazy when every subsequent movie follows the same kinds of characters we've already seen in the past. In order to break this mold and to create stories that are new and fresh in the future, Star Wars needs to take a hard look at the character types it always seems to play into, and figure out how to introduce some new personalities to their universe.
While there are small ways in which the Star Wars characters differ from each other across trilogies, the same basic personalities always make an appearance. There's always the hero (Luke or Rey), the sidekick or side character who also displays heroic tendencies (Leia or Finn), the snarky or suave guy who doesn't play by the rules (Han Solo or Poe), and the wise mentor figure (Qui-Gon, Obi-Wan in the original trilogy, and Leia and Luke in the sequels, though the mentor figure is more complicated with Luke in The Last Jedi). The villains also tend to just be evil for evil's sake, without being too complex (obviously this trope was interrogated a bit more with Anakin in the prequels and Kylo Ren in the sequels, but a majority of villains still come off as very mustache-twirly).
The prequels actually complicate these tropes a little more, despite still falling into them. Anakin is the hero character until his story takes a turn and he becomes one of the villains, and then Obi-Wan sort of takes on the straight heroic mantle. Padme, however, is still sort of thrust into the heroic side character position (which, unless you're Leia, unfortunately, tends to slot a character into "boring" territory).
The sequels also try to mix things up a little more and fail, perhaps partially due to the lack of planning of any sort of overarching story. Finn's role as a sidekick, in particular, seemed like it would be complicated with his backstory of originally being a stormtrooper, but that storyline is pretty much dropped after the first movie, except when they need to bring it up for plot convenience (such as when they need to break into a First Order base and Finn just happens to know how). This is especially disappointing because instead of his character revolving around Rey and being bland, fans could have seen a morally conflicted and guilty character trying to reckon with his past and the trauma he's endured.
In fact, the sequels spend a lot of time setting up potential storylines that would make their characters complex and then not following through on that. Rey could have been more interesting if she'd taken the grey Jedi path that a lot of fans wanted for her storyline, but Star Wars seemed pretty committed to keeping her a typical hero. Kylo Ren certainly complicated the role of villain, but the take becomes a little less nuanced when he suddenly does a full 180 in the last movie to becoming a hero, which is an interesting arc, but in this case, didn't feel quite as earned as it should have. Having villains like Hux or Snoke alongside Kylo Ren also undercuts the commentary on morality that his character is supposed to be making, because they fall into that sort of lazy, typically evil archetype with no motivation other than world domination.
Star Wars also has the MCU problem of writing all of their female characters the same way, and not allowing them to have very distinct personalities. Rey, Jyn Erso, Qi'ra, and Leia all have fairly similar traits of being strong women who are often stoic and not overly feminine (and Leia's personality still feels the most distinct out of all of these women, perhaps because she was the first), which is fine, except it perpetuates the stereotype that a woman cannot display femininity while also being a "strong" character. Padme falls into this a little as well, with a bit of a softer, more feminine energy to her, but still not far off of their tried-and-true female character model that is definitely starting to get old after 40+ years. It also doesn't help that all of these women look pretty similar - they're all young, conventionally attractive, white, and brunette. Star Wars needs to start centering women of all different types, and not relegating anyone who doesn't fall into their model to a side character (such as what happened with Rose).
How does Star Wars fix all of this? The answer seems pretty simple, but it's strange that they still seem to have trouble doing this after all of these years. Star Wars simply needs to create more varied characters. Perhaps the franchise needs to take itself less seriously and introduce some outright goofy characters again, or a hero that is allowed to be funny instead of boring, serious, and stoic. They could also introduce female characters with a variety of appearances and personalities. The animated Star Wars shows seem to do a better job at this than the main live-action series, so maybe they should take notes from the success of shows like The Clone Wars.
They also need to worry less about angering a small group of fans by treading new territory. That was the main reason that The Rise of Skywalker turned out as messy as it did. What fans really want is to see a variety of stories and a variety of people represented on screen, not the same characters over and over, just in a different skin. Playing to certain archetypes is fine in moderation, but at this point, Star Wars is starting to feel a little too formulaic. The franchise needs a refresh, and it needs to find some new and interesting characters to introduce that feel completely distinct from those who came before. Otherwise, Star Wars may begin to find itself a little stagnant, and eventually even totally dead in the water.