There are things that are actually bad that governments have tried to ban and failed. Even if certain regimes try or succeed in banning it in their country, other rival countries will see it as an opportunity. The community really governs crypto currencies, so unless all the devs abandoned their projects it will not die.
I don't even think banks can compete on the technical level, the only way they could right now is to poach the best devs from the crypto community. When giant hardware manufacturers are making mining specific M/B's etc, it shows how much progress has been made.