You're taking an absolutist view. Crypto currencies weren't intended to free people from every constraint of society, just a few constraints, and only to a degree.

Crypto clearly has the potential to make enforcing trade and currency restrictions far more difficult. When it's too difficult to enforce a rule, governments can (1) stop enforcing it; or (2) ratchet up the penalty when someone does get caught as a deterrent. The second option can lead to unpopular disproportionate punishment, and slowly melts away towards the first one (e.g., war on drugs).

Crypto-currency won't take down governments, especially overnight, but they clearly have a long-term potential to alter some levers of power.