Frankenstein is considered a classic because it combines elements of Gothic horror, Romanticism, and early science fiction to create a thought-provoking and engaging story. The novel's themes continue to resonate with readers today, as they explore the human condition, the potential consequences of scientific advancement, and the nature of responsibility. Additionally, Mary Shelley's groundbreaking work has played a significant role in shaping the development of the science fiction genre, earning it a lasting place in the literary canon.