Why an old hull design can limit a young warship

What becomes outdated when a warship uses a hull design created decades earlier?

The limiting architecture is often the internal arrangement of machinery, electrical generation, distribution, and growth margins rather than the outer hull shape alone.

Modern sensors, weapons, and propulsion increasingly compete for electrical power, so generator placement and distribution paths shape the whole ship. A design without sufficient conduits and margins may require its internal systems to be stripped out before a major upgrade, even if the hull remains structurally sound.