Same reason Sasuke always won: Plot Armor. They're both just as useless as the other or any other character without it. It's what decides who lives & dies.
Plot is actually a horrible excuse. Plot is the cause every thing that happens, wins, losses, everything, but they're in story reasons, and logic of why things happen, those should be used when discussing things.
I don't the arguments because where would sasuke be without cm he couldn't even beat fodders also his cm is reason he beat oro or even diedra so sasuke fans have excuses why Naruto solos but seem to forget the power ups sasuke got its hilarious
The CM is not a living entity, nor was it ever his main power source, nor did he have it the whole story + The CM negatively effected Sasuke alot until he mastered it, and thus was able to use it perfectly.
Sasuke had the best grades in his class, graduated at the top of the academy, and was the best in his generation without the Curse Mark, or even the Sharingan...he actually defeated a guy in the prelims of the Chunin exam without the Sharingan or even chakra whilst the CM was trying to take over his body.
None of Orochimaru's techniques worked on Itachi, and Sasuke due to their mastery of the Sharingan. That was made clear, and Deidara had Tobi's help + prepped before the fight, hence having a counter specifically for Sharingan Genjutsu, and a strategy with Tobi.
Besides that, he had the element of surprise, hence randomly attacking Sasuke.
You always overlook alot of things.
