What important new idea did the Abstract Expressionist movement pose that had a major and lasting effect on ar?

The Abstract Expressionist movement introduced the idea that the act of painting itself could be a form of expression and a means of conveying emotion, rather than merely a depiction of reality. This shift emphasized the process and physicality of creating art, allowing artists to explore spontaneity, individualism, and the subconscious. As a result, it encouraged future movements to prioritize personal expression and conceptual exploration, fundamentally altering the trajectory of modern art. The movement's legacy persists in contemporary art practices, where the act of creation remains a central focus.