Markets determine which price is reasonable. It's a collective decision about how much something is worth. Is it reasonable to say bitcoin should be worth less than $10K, $1000, $100 etc...? No, because the price today is not that.
You're misunderstanding something here. It's reasonable and very common to say that the true value of a financial asset is different than its market price; anyone who makes an investment in something is expressing the thesis that the current market price is lower than it will be in the future.
No, I don't misunderstand, I agree with you. Just saying that a market price is the best guess for whatever the "true" price is / should be. Because cyrpto markets are easily accessible across the world to everyone, it will be closer to the "true" value than other markets that are less accessible.
