The non-living cell inclusions are manufactured in the plant since they are products of metabolism, thus facilitates physiological growth and energy requirement.
The inclusions store nutrients such as glucose and lipids that are essential for the energy requirement in plants. Additionally, they are also responsible for pigmentation in plants, therefore giving the color to the leaves and flowers, and lastly, the inclusions act as organic polymers that provide structural support to the plant. Therefore, it is important that plants manufacture non living inclusions in their cytoplasm.
Pantankar,V. V. (2020).Cell Biology Introduction and Plant Cell, Paper-II.