Water’s status as an element predates Aristotle. In the fifth century BCE, Empedocles described four enduring “roots” underlying ordinary matter: earth, water, air, and fire. Aristotle later incorporated those four into a much more systematic physics. In On Generation and Corruption he associated water with the qualities cold and moist and treated it as one of the primary bodies from which compounds were formed and into which the elements could transform.
The importance of Aristotle was not that everyone in 350 BCE suddenly agreed with him. It was that his natural philosophy became an unusually comprehensive framework covering matter, motion, the heavens, meteorology, generation, and biology. After the Aristotelian corpus became widely available in medieval Latin Europe, his natural works became central texts in university education and remained major reference points into the Renaissance.
The chemical revolution broke the old category itself. Eighteenth-century experimenters learned to isolate and characterize different gases, and work by Henry Cavendish, Antoine Lavoisier, and others showed that water could be made from what became known as hydrogen and oxygen. Later electrolysis made its decomposability visually unmistakable.
So this card spans two different meanings of element. The classical element was a fundamental constituent within an explanatory physics; the modern chemical element is defined by atomic identity. Water ceased to qualify under the newer concept because it is a compound.