There are currently about 7 billion people on the planet, all of which require water to survive. Even without the direct consumption of water, water is usually in most other beverages that people consume. Also, many of these billions of humans use massive amounts of water everyday to do laundry, bathe, wash dishes, and so forth. Many animals require water to survive as well.
Also, humans and animals requiring frequent water consumption has been a thing for billions of years. Obviosuly Earth’s water supply is not infinite. How have we not already exhausted all the water the Earth has to offer?