1940s era Battleships are probably unnecessary gigantism, but it should be noted that the 'massive' ironclads of the 1890s were completely obsolete by the much

1940s era Battleships are probably unnecessary gigantism, but it should be noted that the 'massive' ironclads of the 1890s were completely obsolete by the much bigger, heavily armored Dreadnoughts. (The battleships of 1890s were too small and impractical, leading to the development of the 1900s era bigger ships) The only reason Super-Battleships of the 1940s didn't work was because aircraft carriers were better. Whenever a bigger ship went up against smaller ones, the results were spectacular. See Bismark vs HMS Hood (Battle of Denmark Strait) for example. Battleships basically shoot 1 ton per gun per shot, and have broadsides of 9 guns in a unified and coordinated Salvo. These are the biggest guns ever made. ------ Big guns shoot further. Bigger ships can afford thicker steel for more armor. Smaller guns of the Destroyer and Cruiser classes simply cannot damage Battleships in combat, too little range and even if they had the range, not enough penetrating power to go through the armor. So if you have a smaller ship, you gotta sail into range while giving your opponents battleship first strike (and all 1940s ships had computerized firing systems, mechanical computers but they worked). So they were quite accurate with these big guns too. ------ Tanks went a similar evolution in Germany. Other countries (France / Russia) put effort into heavy tanks, but Germany first focused on light tanks... Until the German shells were bouncing off of their foreign counterpart's armor. So the Germans later made King Tigers, as bigger is in fact better in some circumstances.