Short term the banks might be able to improve their services by using blockchain. But long term, they are going away in lack of need for their services. Case is, in the time coming up now, most bankers will be aquiring cryptos themself, and by that, they will individually hold significant value that they will not work to stop or halt in any way. Everyone is oneself closest as it is said. The same goes for government. Call it corruption if you like :) But thats simply how things roll. This will maybe not be the case in every government, and every bank, but enough that there will be safehavens for the cryptoadapters.