Why did structuralism fail as a working psychological learning approach?

Structuralism failed as a working psychological learning approach primarily because it focused on the analysis of conscious experience into basic elements, which proved to be subjective and difficult to measure objectively. It also lacked practical applications and was criticized for oversimplifying complex mental processes. Additionally, the rise of behaviorism offered a more observable and scientific approach to studying human behavior, leading to the decline of structuralism.