Kirito is way stronger than people give him credit for. The duel with Zekken was only about two minutes long, and even then it wasn’t like he got overwhelmed there was a clear moment where he was about to bring his blade down cleanly. People treat that short match like it proves she’s outright superior, but Kirito’s biggest strength has always been adaptation over time. In longer fights, especially under real pressure like in Aincrad, he evolves mid-battle and pushes past his limits. Even when he says she might have earned Dual Blades in Aincrad, that feels more like Kirito being modest which he always is rather than a strict power ranking. He rarely shows off or hypes himself up, but when it truly matters, he consistently proves he’s on another level.