Because you can define value if money has any value.

"People are the ones who give money its value. Money by itself, like a piece of paper or a coin, isn't worth much. But because everyone agrees on what it's worth, we can use it to buy things, pay for services, or trade. People work, invent things, and offer services, and money helps us exchange these things easily. So, without people, money wouldn't have any meaning or use!"