>>64130654
Both. The zero had great performance but at the cost of being a flimsy rice cooker whose avionics made the F4F look like an F-111 Aardvark. Then in the mid (by burger time scaling) war the USN improved BFM training to play to their strengths against it.
Late War allied fighters were so mechanically, operationally and etherically better than their 1940/41 counterparts in every way they are different animals all together: armament, airframe, reliability/survivability, gunsights, compressibility to say nothing about 2000 HP monster engines with enough torque to twist the nipples of god himself. The Zero did not have such a glow up.