Why is Superman considered the prototype for costumed superheroes?

Superman is considered the prototype for the modern costumed superhero because he perfectly personified the archetype upon his debut in Action Comics #1 in 1938.12

While various fictional characters in pulp magazines, comic strips, and radio foreshadowed the genre, Superman was the first to combine the essential elements that define the superhero today. These hallmarks include:12

• Superhuman Powers: Possessing extraordinary abilities, such as immense strength and invulnerability, which are used to fight crime and villains.123
• Altruistic Mission: A commitment to heroic, selfless action.1
• Defining Costume: A distinct visual identity that became a standard for the genre.12
• Dual Identity: The practice of functioning in the "real world" through an alter ego—in his case, the mild-mannered reporter Clark Kent—which creates a compelling tension between his ordinary life and his heroic persona.13

Following his immense commercial success, Superman spurred the creation of an entire industry, serving as the standard-bearer for the many costumed characters that followed.123