When it comes to Star Wars spinoff projects that are based on one specific character, Andor has proven to be the exception to the rule. The Book of Boba Fett was an unnecessary side adventure that didn’t even feature its titular character for several episodes, Obi-Wan Kenobi failed to develop any insight into the Jedi Master’s relationship with his former apprentice, Solo: A Star Wars Story became the first box office flop in the franchise’s history, and Ahsoka was completely incomprehensible for those that hadn’t already dedicated hundreds of hours of Dave Filoni’s animated content. While he is a fan-favorite character among Star Wars fans, Mace Windu does not need a spinoff film or television show.
The Timeline of a Mace Windu Spinoff Does Not Work

Windu has never been a particularly compelling character, as he is a stern Jedi leader who is often subservient to Yoda, but lacks the compassion of Obi-Wan Kenobi. The only draw of a potential Windu spinoff is Samuel L. Jackson, whose performance was one of the few within the prequel trilogy that was greeted with acclaim. However, Jackson is too old at this point to feasibly play Windu in events that take place before he died in Star Wars: Episode III – Revenge of the Sith. While Jackson has himself hinted that Windu may have survived being thrown off the Senate building by Palpatine, the Star Wars franchise has proven that retconning character deaths is rarely a good thing; the unexpected revivals of both Palpatine and Darth Maul led to more questions than anything else, and made the events of the films feel less powerful in retrospect.

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It would be very hard to find a young actor to capture Jackson’s mannerisms to play a young Windu in a Star Wars prequel, as he is one of the most distinguishable movie stars of all time. Even Alden Ehrenreich, who did a much better job playing Han Solo than he was given credit for, got stung with criticism because audiences were unable to avoid comparing him to Harrison Ford. Given how iconic Jackson’s personality is, there would be a significant challenge for a new actor not to feel like they are doing an impression. While a digitally de-aged version of Jackson was used to play a younger version of Nick Fury in Captain Marvel, this is not a technique that Lucasfilm should rely on, and would certainly have an uncanny effect if it were for the titular character in a Windu spinoff.
Star Wars Needs To Move Away From the Prequel Era

Windu’s story would not present any new insights about the Jedi Order, as their failings have already been well-documented in The Last Jedi, The Acolyte, and many episodes of The Clone Wars. The closest thing fans have gotten to a solo Windu project are the episodes of Tales of the Jedi, in which he teamed up with a young Count Dooku. The miniseries indicated that Windu had not changed his attitudes towards Jedi protocol at all during his career, as he remained fiercely loyal to the superiority of the Council until his death. Having a stagnant character as a main protagonist doesn’t make for good storytelling; if there were to be a series about a famous Jedi emerging during the Golden Age of the Galactic Republic, more nuanced characters like Qui-Gon Jinn or Quinlan Vos might make for better protagonists.
The Star Wars franchise needs to move beyond the prequel era, as the final episodes of The Clone Wars wrapped up this portion of the timeline on a conclusive note; the most successful Star Wars projects in recent years, such as Andor and the first season of The Mandalorian, have succeeded in digging into eras in which there are much more open questions. The franchise is also desperately in need of new blood and radical change, as it is hard for Star Wars to accept new fans when it is constantly developing projects to appease nostalgic viewers. While Windu is a character that has had his moments throughout the Star Wars franchise, it is best for him to be left in the past so that the galaxy far, far away can develop a promising future.