Why are the leaves of plants usually painted as ink leaves in flower-and-bird paintings?

As an art, painting often uses the description of scenery to express some thoughts and emotions. The real thing may not look like photography. If so, meticulous painting should be the closest, while freehand brushwork in Chinese painting has more exaggerated elements in this respect, and its purpose may be to express meaning. Some even focus on the brushwork and color application of Chinese painting, such as painting bamboo, which can include bamboo, ink bamboo, cinnabar and snow bamboo. Lotus leaves are particularly prominent when painting ink leaves. The author often paints lotus leaves in layers of ink, and then embellishes a budding or blooming red lotus flower, achieving the artistic effect of color balance. Personal views are for reference only, please criticize and correct me.