
Ancient propulsion machinery that was obsolete decades ago, with parts and experienced operators no longer available.

Main guns that have just a 24 mile range.

Main guns that can only be used by bringing the ships close to shore and even short-range anti-ship missile batteries.

Main guns, turrets, and barbettes that would have to be removed and magazines rebuilt before a significant missile battery could be installed.

Architecture and armor designed before the era of modern anti-ship missiles.

Numerous manual systems that require a much larger crew than would be required to operate more modern systems.
I have zero disrespect for the Iowa class battleships, but it is time to put nostalgia on the shelf and let them remain in their current role as museums.