Why Cold War ships still dominate many fleets

What recent naval-history fact is most striking about today's fleets?

Many major warships now in service are Cold War designs, much as World War II fleets long relied on ships built in the previous war.

Many of today's carriers and other large combatants first entered service during the Cold War. That resembles World War II fleets, which relied heavily on capital ships built around the First World War. USS Nimitz gives the clearest example: commissioned in the 1970s, she had passed fifty years in service when discussed. The comparison shows how heavily a fleet can depend on ships built for an earlier strategic era.