1) there needs to be a time jump.......simple as that......somewhere along the lines a few years have to pass, so that sasuke actually becomes a worthwhile villian...

2) however, there can't be a time jump.....because the akatsuki is after naruto, and they wouldnt leave him alone for like, 3 or so years.....

3) but.....one of the akatsuki members after naruto is itachi, and neither naruto nor sasuke are strong enough yet to defeat itachi, so there needs to be a time jump (and it has to be one of those two who defeats him).....

so.....here lies the paradox