The answer to the question why do plants need water may be obvious. Even grade school kids can provide a definitive answer. But there are underlying layers that can explain the importance of water for plants.
Every living thing on our plant need water as one of the basic necessities to survive. It is also the means to grow and retain life. Without water, all organisms are surely going to struggle or worse die.
If the human body is comprised of 70% water, plants must be composed of 95% water. Imagine yourself if you’re a plant and compare the amount of water to take every single day. It is that much. As a matter of fact, plants are the only living thing that needs water the most in order to continue growing and appearing in our surroundings.