Star Wars has undergone some rough luck over the past twenty or thirty years, constantly changing plans as the minds behind the franchise struggle to determine what fans actually want. Though a variety of modern projects have been halted or scrapped, there are a ton of older ideas that never got their moment and could have been interesting.
When the sequel trilogy was coming out, it seemed a new Star Wars project was announced every few days. Today, most of those didn't make it to the filming phase, let alone to the screen. While there will almost certainly be Star Wars media for the next thousand years or so, the series has a long and proud history of canceling ideas and starting over halfway through.
Back in the early 80s, when George Lucas was still in charge of the franchise he started, he threw out ideas for Star Wars spin-offs in casual conversation all the time. Lucas spoke of a movie entirely about droids, possibly led by C-3PO and R2-D2. He brought up a cinematic outing about Wookiees, set on their home planet Kashyyyk and built around their unique culture. In 1980, around the time Empire was released, Lucas was already describing the franchise as a nine-film saga. While it did eventually reach that milestone, it did so in a way he never could've predicted and with several other creators at its helm. Lucas evidently had big plans for the franchise that never came to fruition, but there's no way of knowing whether those projects would be better or worse than the modern output.
Many scrapped projects evolved into future productions, often through a variety of bizarre trades and transfers. Fans of The Mandalorian probably know that the series gradually formed from the shell of James Mangold's Boba Fett movie, which later morphed again into The Book of Boba Fett. A once-pitched animated series about a group of Jedi Padawans on a coming-of-age adventure, which was the final Star Wars project George Lucas had involvement in, later became a story arc in The Clone Wars series. The aforementioned Wookiee concept might have morphed into the much-maligned Star Wars Holiday Special. The franchise doesn't always destroy everything it lets die, but it does often repurpose concepts and premises to better fit future plans.
A ton of Star Wars projects got the ax very recently due to one apparent disaster: the financial failure of Solo: A Star Wars Story. Han's solo project was the second film released under the Star Wars Stories brand, after Rogue One, which was a monumental success. After Solo failed to live up to expectations, Disney abandoned the multiple in-progress films under that umbrella. While there are almost certainly some projects fans never heard of that didn't make it out of the pitch phase, there are several known films that hit the cutting room floor. Boba Fett's movie was wrapped up in that crash. A film about Jabba the Hutt, reportedly garnering some interest from Guillermo del Toro, was scrapped with little detail. A film centering on the iconic Mos Eisley Cantina was barely announced before it was canceled. Disney makes extremely swift decisions with the direction of the franchise, often destroying tons of possibly interesting projects in the process.
Star Wars doesn't just announce and abandon projects on the big screen, there are a few interesting TV or streaming series that never made it to air. By far the most interesting project that the franchise abandoned was called Star Wars: Underworld. This live-action TV series was pitched by George Lucas in 2005, just after the release of Revenge of the Sith. It was described as an adult take on the galaxy, an anthology that would explore darker corners of the franchise. Writers like Ronald D. Moore of Star Trek fame, and Tony McNamara, who would go on to write Cruella, were attached to the project. Over fifty scripts for one-hour episodes were written, and concept art was supposedly produced, but the show was not to be. Around 2010, the series was parked due to budget issues. The team involved wanted the project to look like the films, but didn't have the budget to make that possible. When Disney acquired the brand, their squeaky clean family image made it extremely unlikely that anything like Underworld would ever see an official release.
There are a ton of games and an ocean of books pitched by one creator or another that never saw the light of day, but Star Wars' logic behind these choices is rarely understandable. While the franchise seems to have found a direction that is working, with big-budget trilogy films in the theaters and spin-off material on Disney+, nobody knows how long that will last. The Star Wars franchise features some of the most interesting development stories, cut content, and evolving projects in the cinematic world.