Gone the Age of the Battleship
1) Their machinery is very, very old. We no longer have the ability to readily make spare parts. We would end up having to cannibalize the two museum ships (the New Jersey and Missouri) for the inevitable breakdowns.
2) The guns are also very old, and we no longer have the industrial base to work them. They need new liners for the barrels every 250 or so shots, and we haven’t made any new ones in decades. We’ve been living on the spares made during World War II ever since, and we simply can’t make more without a huge investment in retooling.
3) They are crew hogs. During World War II, it took over 2,700 men to run the ships. Since their rebuilding in the 1980’s, their complement was reduced to between 1,500 and 2,000 crew — enough to run three or four modern combatants.
4) The Iowa herself is “damaged goods.” The center gun of her second turret exploded in 1989, and it was never fully repaired — she ony has six functional main guns.
5) The United States hasn’t made an opposed landing in 55 years. We can pretty much “walk” ashore anywhere we might need to. Our military superiority is such that we simply don’t have to worry about such things.