>>281472720
When Lancer launched Gae Bolg on Saber, he didn't state that it couldn't miss beforehand. We only learned its properties later on, well after this fight. Lancer stated that the attack was sure-kill, but nearly all Noble Phantasms are sure-kill. Gae Bolg, Excalibur, Nine Lives, Caladbolg, these are all weapons designed to end the enemy's life in one strike. Nearly all of them fail. Even the VN's most powerful Noble Phantasm, Ea, fails to kill anyone.
The reason people latch onto Gae Bolg specifically is because, after this fight, we see a description of it and learn that it's a strike that reverses causality. It's the VN's first example of an esoteric power that fucks with the laws of physics, so it retroactively became a big deal. But something you have to understand about Type-Moon is that esoteric physics-defying bullshit is usually just a parlor trick. At the end of the day, do you know what the greatest power in any Nasu story is? Raw brute force. This principle is present in Notes, Tsukihime, Fate and even Kara no Kyoukai. The most power individual in KnK isn't the bitch who can one-shot (almost) anything or the thousand-year-old monk with a magic monster apartment. No, it's the bitch who twists things. Raw power, completely inelegant brute force.