The problem is, people are still using Bitcoin as currency, when in reality its just a check/promise.
There is nothing backing any of these crypto currencies.
Yes, almost all modern currencies are “fiat” currencies that are not backed with traditional assets like gold, but they are backed by the power of a government to tax and require that any transactions be made using their currency within their spheres of control.
Bitcoins were designed to disrupt the banking systems that allowed various entities to tax the transaction by effectively bypassing them. They have some value as a transactional vehicle, like a money order, but eventually you still need to cash that money order out.