With that in mind, imagine, if you will, a Star Wars trilogy that was all about the close friendship and eventual ruin of two great friends, Anakin and Obi-Wan. Even though Liam Neeson was the best part of Phantom Menace, I don't need Qui-Gon. I don't want to see Anakin as an annoying little boy who can't act, and I don't want to see him as smart-mouthed teen who makes Obi-Wan look like a cranky, overprotective mother. I want to see two 20-something badass wizard-knights trolling the galaxy and ensuring order.
There's a scene in Revenge of the Sith when Obi-Wan and Anakin are laser-sword-fighting on the hell-planet when Obi-Wan, clearly feeling hurt and betrayed, yells out, "You were supposed to be the chosen one!" And we, as the audience, feel nothing. The ultimate divorce between Obi-Wan and Anakin carried no emotional weight. The only evidence of their friendship was when Anakin said something along the lines of "You know, Obi-Wan, you've always been a good friend to me," at some point in Episode III, about 30 minutes before they fight each other. That's the only glimpse of friendship we get. When a character flat out tells the audience, "No, we're very good friends, trust me."
"Character development, character development, exposition, tragic flaw, character development."
But let's say that the first two movies were devoted solely to Obi-Wan and Anakin training and being Jedi warriors, kicking ass and being best friends. They're Butch Cassidy and the Sundance Kid, in space. A friendship that you believed as strongly as you believed that Luke, Leia and Han would be forever bound to each other. Not only would movies about two Jedi warriors be objectively more entertaining than movies about trade federations, galactic senates and stuffy, over-bearing Jedi councils, but it would make the eventual Obi-Wan and Anakin betrayal so much more powerful. We already knew going into the prequels that Anakin was going to turn into Vader, so making him a whiny, aggressive, cocky little shit does nothing for the character. When Obi-Wan slices up Anakin on the hell-planet, we shouldn't be saying "Finally," we should be heartbroken that a character that we'd spent two movies knowing and loving had to chop up his best friend, another character that we'd spent two movies knowing and loving. The only way that Anakin's transformation into Vader can make any kind of impact is if his fall from grace is an actual fall, and not a stumble.