Naruto could have killed sasuke many times but that's not wat he wants to do he wants to save his friend instead, after the pain fight until now naruto is still more powerul than sasuke stated by zetsu.
notice at the valley of the end naruto was stronger, more powerful even though sasuke use his cm2 while sasuke tried to kill naruto twice before naruto tried to be serious and in the end while naruto held a rasengan and sasuke held a chidori, sasuke sasuke put it in naruto body but naruto could have countered but decided to hit sasuke headband bcuz sasuke said he wouldn't put a scratch on his forehead. current, now, naruto is more powerful even with sasuke ems thaaat we know little of because naruto almost is unlimited in chakra alone the kid has a tone combine with the fox produced 100x the chakra he has and it's not even the full extent of the fox chakra yet and he could use sage mode which make the kd invincible if he could combine the two modes + the fox as a backup.
sasuke in the other end is indeed strong and powerful but doesn't have the kind of chakra to use all his technics, amaterasus, tsukuyomi,susanoo, susano arrows these move took a tone of chakra from him and ems doesn't gives you more jutsu except one new, ems is unblindness improve ms for real with a new technic only because of the two combine eyes and a little add of chakra which is sasuke chakra + itachi chakra= sasuke ems.