Cryptocurrencies do not need to be adopted on the same level as state-issued fiat currencies in order to achieve this goal. So long as they provide a means for

Cryptocurrencies do not need to be adopted on the same level as state-issued fiat currencies in order to achieve this goal. So long as they provide a means for some people who wish to live outside the state, evade taxes, launder money, and channel resources into actions which harm the state and its ability to enforce laws, it succeeds. As long as there are privacy problems being solved by their use, they will appeal to people who value that privacy over living under the control of state governments.