All money has always been about perception, whether we used paper, shiny rocks, or sea shells as money, it’s always been about perception. Is it real or counterfeit, do you trust the person you’re transacting with, are enough people you know using it, and will people with weapons show up to protect your money if someone else tries to steal it?
The “people with weapons” part turns out to be a key component. The novel thing about crypto is that you are less reliant on the “people with weapons” to protect you and tell you what you’re allowed to do with your money, and more reliant on the “people with encryption”.