No I do not think that banks can be destroyed by the bitcoin itself, the government will indeed stop this and the banks itself also has enough power to stop this easily.
i think no one can stop bitcoin not the governments and nor the banks, banks and governments have to admire the importance of bitcoin and they have to accept bitcoin as legal currency. the banks will also start accepting bitcoin in future.
yes i also agree with you i also think that no one can stop bitcoin from becoming a global currency. evenr the government cannot stop it, i think in future the banks and states will consider bitcoin as legal currency and then bitcoin will become more predominant and trusted.