It all depends on what we think of as value:
"This up and down or rise and fall of the value of cryptocurrency is what crypto investors take advantage of to earn profits."
Down and up? If I look at the ecosystem, why would realizing profit in fiat money be so interesting to me? If the ecosystem works well and really offers a solution for something meaningful and useful that I can use in everyday life, I don't think I'd be particularly excited about converting the cryptocurrency to fiat money 😉