Why are there no battleships anymore?

Battleships were useful to both the Royal Navy and the US Navy at various times in their history. Powerful and heavily armed warships designed to engage enemy surface ships in combat. They were the mainstay of naval power for many years, and played a vital role in several major conflicts.
During World War I, battleships were instrumental in the naval arms race between Britain and Germany. The Royal Navy’s Grand Fleet, composed mainly of battleships, played a key role in the decisive victory at the Battle of Jutland in 1916. A win that secured the British blockade of Germany and helped to ensure victory over the Kaiser.
During World War II‘s Pacific fighting, the US Navy’s battleships played a key role in defeating the Imperial Japanese Navy at the Battle of Midway in 1942, a turning point in the Pacific Theater of World War II.
Battleships also found themselves used for other purposes, such as shore bombardment and convoy protection. During the Normandy landings in 1944, battleships provided crucial support to the Allied troops by bombarding German positions along the coast. In the Pacific, battleships protected convoys of ships carrying troops and supplies to the front lines.
However, the usefulness of battleships declined with the advent of new technologies, such as aircraft carriers and missiles. Battleships were vulnerable to attack from the air, and their large size and high operating costs made them less practical in modern naval warfare. As a result, many navies decommissioned their battleships in the latter half of the 20th century.

The pointy end of the spear became aircraft, guided weapons (missiles and torpedoes) and submarines—not the guns on board a ship—thus largely ending of the utility of the battleship in the open ocean.
Battleships were once the most powerful and feared naval vessels in the world. They were massive, heavily armored, and carried an array of powerful guns that could devastate targets at long range.
However, despite their once-dominant status, battleships have become obsolete in modern warfare.
USS New Mexico (BB-40) found itself unwanted by any global navy after World War II. Decommissioned in 1946 and sold to Lipsett for $381,600 ($4.4 million in 2020 dollars) in 1947.

“The episode got off to a bad start when a storm broke the tow lines off the battleship. It drifted away in the Atlantic (with Lipsett employees aboard) for three days until a US Coast Guard plane found it and the tow could be recovered.
Lipsett planned to scrap the ex-USS New Mexico and other large, expensive warships in Newark, NJ which had good railroad access. But that city was redeveloping the waterfront for postwar use. The mayor told Lipsett to take the ex-USS New Mexico elsewhere. Lipsett, a subsidiary of the then-powerful Luria company, protested that all the paperwork was in order and they had every right to break up WWII battleships in Newark.
The mayor in turn essentially said he didn’t care, and threatened to have city-owned boats hose down the tow tug crews with firefighting foam.
After a weeklong standoff (which was national news for several days), the federal government brokered a compromise that Lipsett could scrap only three ships in Newark, and had to be finished in nine months or less.” Source
There are several reasons for this, including changes in technology, shifts in naval strategy, and the rise of air power.
To understand why battleships have become obsolete, it is important to first understand the history of these ships.
Battleships first became developed in the late 19th century. Moreover, as naval powers sought to build larger and more powerful warships. The first modern battleship was the British HMS Dreadnought, which was launched in 1906. Dreadnought was revolutionary in several ways, but perhaps its most important innovation was its use of an “all-big-gun” armament, which meant that it carried a large number of heavy guns capable of firing shells over long distances. This made it vastly more powerful than any previous battleship, and it set a new standard for naval warfare.
In the years that followed, other naval powers began to build their own battleships, and a naval arms race ensued. The most significant of these powers were Germany, which sought to challenge British naval dominance, and the United States, which emerged as a major naval power in the early 20th century. Battleships played a key role in World War I. Where they became used to blockade enemy ports, protect convoys. And engage in fleet actions against enemy battleships.
Despite their important Naval standing in World War I, battleships began to face significant challenges in the years that followed.
One of the biggest of these challenges was the development of new technologies, particularly in the area of naval aviation. The first successful carrier-based aircraft became developed in the 1920s, and by World War II, aircraft carriers had become the dominant force in naval warfare. See our piece: Understanding The Value Of The Carrier: Was The Navy Reluctant To Embrace Air Power?
This was due to several factors, including the ability of aircraft carriers to project power over long distances, the ability of aircraft to attack targets beyond the range of battleship guns, and the ability of carriers to launch surprise attacks against enemy fleets. See our piece: Battle of Taranto : The Battle that Changed War & Battle of Taranto 1940 : The Emergence of the Carrier in Naval Combat
Another factor that contributed to the obsolescence of battleships was changes in naval strategy.
In the years leading up to World War II, naval strategists began to focus more on the importance of speed and mobility in naval warfare. This led to the development of smaller, more agile ships. Such as destroyers and cruisers, better suited to the kind of fast-paced, mobile warfare that was becoming more common. Battleships, with their massive size and slow speed, became seen as increasingly outdated in this new era of naval warfare.
The rise of air power was another factor that contributed to the decline of battleships. In the early days of naval aviation, aircraft became limited in their range and payload capacity. As a result became primarily used for reconnaissance and scouting. However, by World War II, aircraft had become much more advanced, and were capable of carrying powerful bombs and torpedoes that could sink even the largest battleships. This made battleships vulnerable to air attack, and forced naval strategists to rethink their approach to naval warfare.
Despite these challenges, battleships continued to play a role in naval warfare throughout World War II and into the Cold War.

Battleships were used extensively in the Pacific Theater of World War II, where they played a key role in amphibious assaults and provided fire support for ground troops. Battleships were also used in the Korean War and the Vietnam War, where they provided fire support for ground troops and attacked enemy positions along the coast.
The Cold War period became a time of intense geopolitical tension between the United States and the Soviet Union that lasted from the end of World War II in 1945 until the collapse of the Soviet Union in 1991. However, Battleships played a relatively minor role in this conflict.
During the early years of the Cold War, battleships were seen as an important symbol of military might and a key component of naval strategy. The United States and the Soviet Union both maintained large fleets of battleships, which were used for a variety of purposes. One of the primary roles of battleships during this period was to act as a deterrent against potential aggression by the other side. The mere presence of a battleship in a region could send a powerful message to other nations, and both sides used battleships to project their power and assert their dominance in key regions around the world.
Another important role of battleships during the Cold War was to provide fire support for ground troops. Often used to provide artillery support for amphibious assaults and other military operations. Particularly in areas where air support became limited or unavailable. Battleships also became used to attack enemy positions along the coast and to provide cover for troops on the ground.
In addition to their combat roles, battleships also played a key role in intelligence gathering and reconnaissance during the Cold War.
Equipped with advanced radar and surveillance systems, which allowed them to detect and track enemy ships and aircraft. Also used to collect signals intelligence. And other types of intelligence that could become used to inform military decision-making.
Despite their continued importance during the Cold War, battleships began to face significant challenges in the years following World War II. As naval technology continued to evolve, battleships became increasingly vulnerable to attack from other naval vessels and from the air. As a result, this led to a shift in naval strategy. With both the United States and the Soviet Union placing greater emphasis on aircraft carriers. And other types of ships better suited to modern naval warfare.
By the 1980s, battleships had largely become relegated to a secondary role in the American and Soviet navies. Many battleships became decommissioned and scrapped. While others became converted to other types of ships or used for training and research purposes. Despite their decline in importance, battleships remain an important part of naval history. And lastly, many still preserved as museums or monuments to the naval battles of the past.

scrapping the warships of WWII – wwiiafterwwii (wordpress.com)
Why are there no battleships anymore?