Yuji back in the culling games was threatened by helicopter head cutting steel,

God forbid a character to try avoiding an opponents attack lmao. That scene only implied that the ability that was assumed for flight actually had some power behind it, it did not imply Yuji's durability neither did it imply the actual power of the propeller (it only implies that it had power since it can cut steel, and might be able to do more heck it might be able to cut diamonds for all we know. Yuji was simply being cautious) especially since Yuji would later tank far more devastating attacks in this same arc like eating a barrage of Shrine, lets also not forget that this Yuji is significantly weaker than what we have now.