The F-8 Crusader's point-defense limits

Why is the F-8 Crusader sometimes considered unable to compete with 1960s fighters such as the MiG-21?

Its close-range performance was praised, but the comparison questioned its longer-range missile capability and broader mission flexibility. Sparrow compatibility was explicitly uncertain.

The F-8 Crusader is assessed here as an excellent fleet point-defence fighter within gun and infrared-missile range. Its limitation in this comparison is longer-range combat. Whether the Crusader could carry Sparrow is explicitly uncertain in this assessment. The MiG-21 is treated as a step toward a broader combat role through dogfighting, ground-attack ordnance and radar-guided missiles.