Everyone here is possibly wrong, in human civilization, over large spans of time, all currency has historically became zero.
So if bitcoin goes to 0 USD, probably USD is also 0?
So if bitcoin goes to 0 USD, probably we don't need USD, think Star Trek.
So if bitcoin goes to 0 USD, within next 20 years, it's unlikely unless super computers or quantum computer take a leap forward (shrunk down to a laptop instead of a freezen within a freezer) and we can hack bitcoin like a phone app.