All well-told stories involve a main character and an influence character, who seeks to persuade the main character to adopt an alternative point of view. Whether the main character adopts this alternative point of view will determine if the story ends in success or failure and if the main character resolves his or her personal problems. Regardless, one of these characters will change and the other will remain steadfast.
For example, in A New Hope, Luke is the main character, and Obi-Wan is the influence character. Initially, Luke is driven to test his skills. Obi-Wan persuades him to stop testing himself and trust his feelings. In a leap of faith, Luke embraces Obi-Wan’s point of view when he turns off the targeting computer and shoots the proton torpedo into the main reactor, destroying the Death Star. As a result, he became a hero.
In Empire Strikes Back and Return of the Jedi, Luke is the main character, and Vader is the influence character. Vader seeks to tempt Luke to join the dark side. Luke remains steadfast. In a leap of faith, Vader turns back to the light and destroys the Emperor to save his son. As a result, the Empire is defeated, and Luke fulfills his destiny.
In your version of the prequels, Obi-Wan is the main character. Without a character who forces Obi-Wan to wrestle with his inner demons and consider changing his point of view, the story will lack emotional resonance. Ultimately, this edit will be impossible to pull off because no prequel focuses on the relationship between Obi-Wan and Anakin.