Proving that there are still so many possibilities to explore in Star Wars, Rogue One: A Star Wars Story stands apart from the rest of the movie franchise in a few ways. It's much bloodier and a little more bleak than the other films. And though the entire series is about politics and war, no other Star Wars installment has seen as much on-the-ground military action as Rogue One. It's also a different type of story because it's missing a component that's of serious consequence to every other Star Wars movie. There are no Jedi in Rogue One, and their absence is deeply felt. There's a very good reason why the Order isn't represented in this part of the timeline. Most of the Jedi were killed by the Galactic Empire at the end of Revenge Of The Sith, save a couple who went deep into hiding. That's why the reveal of Old Ben Kenobi's true identity and his subsequent training of Luke Skywalker in A New Hope are so significant: together, they were resurrecting a dead religion.
When the prequel trilogy begins, the Jedi are a robust group with strong leadership that includes Mace Windu and Yoda. Obi-Wan is an apprentice of Master Qui-Gon Jinn in The Phantom Menace. They're both astonished to meet an extremely force-sensitive boy living in poverty with his mother on Tatooine. The Jedi Council believes Anakin Skywalker is too young and volatile to be trained, but they reluctantly give Obi-Wan permission to begin his training after Qui-Gon's death. And they basically sign their own death warrants with that decision. Anakin is too emotionally erratic to resist the pull of the Dark Side. He becomes a friend and then a servant of Senator Palpatine, known also as the Sith Lord Darth Sidious. And he learns that a lot of what he believed about the Jedi as a kid is factually incorrect.
Skilled and righteous, the Jedi are the largest obstacle lying between the Sith and complete control of the galaxy. So Palpatine makes sure that each soldier in the army of clones developed under the guise of defending the Republic be programmed to kill the Jedi training them when the Sith say the word. This command bears the innocent sounding name of "Order 66" and names the Jedi traitors to their government.
Anakin participates in the slaughter of the Jedi too. He accepts the name Darth Vader and is dispatched to the Jedi Temple to kill any Jedi or Jedi trainees he finds there, even younglings. As enemies of the Empire, the Jedi are wanted individuals after Revenge Of The Sith. Hence Obi-Wan's return to Tatooine and Yoda's exile in the Dagobah system.
So Rogue One falls between periods of Jedi activity. Soon after the plans are delivered to the Rebel Alliance, R2-D2 will deliver Princess Leia's plea to Obi-Wan. But for now, all that's left of the Jedi is the rebels' trust in the Force. And though Chirrut Îmwe is more devoted to the Force than any other Rogue One character, he's a monk and not a Jedi Knight.
The Jedi are important to Rogue One because they're not there. It feels wrong that there are no masters or apprentices in this movie, because it is wrong. The Empire leadership were so afraid of the Jedi that they sought to eliminate them, so obviously the Rebel Alliance become much stronger once the last of the Jedi resurface.