Why the missile-only warship had a very short design window

How fully did navies accept the claim that missiles would replace naval guns?

Only briefly and selectively; Long Beach fit the idea for a narrow early-1960s threat window before changing aircraft and missiles restored the value of guns.

Navies debated the claim that missiles would replace guns, but few designs embodied it as completely as the original concept for USS Long Beach. In the early 1960s, her long- and short-range missile batteries appeared to cover aircraft and surface threats at every useful distance. President Kennedy's insistence on guns was therefore not initially a response to a clear gap in the design logic. The logic aged almost immediately as anti-ship missiles and strike aircraft became smaller, faster, and more capable. The US Navy's return to guns on cruisers shows how quickly a seemingly complete missile envelope became too narrow for an adaptable warship.