Why Second World War armor does not defeat modern missiles

Why do some people claim a Second World War armored ship could shrug off a modern missile?

The claim overstates armor and ignores buoyancy, subdivision, system vulnerability, and the missile's large explosive warhead.

Older ships may have thicker bulkheads and more internal armor, yet their steel, systems, and damage-control arrangements belong to another era. Comparisons between ships and fixed bunkers fail because a floating hull must preserve buoyancy and stability after the hit. Subdivision remains the most important protection because it limits flooding and preserves the hull after local damage. Large missiles combine kinetic impact with warheads big enough to overwhelm any simplistic armor argument.