I doubt that politicians will want to implement blockchain technology. Many of them are in power only because of election fraud. As to the cryptocurrencies this is a good way for poor countries to have salaries at the level of the which is produced in the developed countries. But it requires certain skills that do not have people in poor countries. Now education has a real price.
There is a difference between the blockchain and bitcoin, banks and governments are fine with the blockchain and are in fact making their own research on the subject but they hate bitcoin, bitcoin is a threat to them for the simple fact that is something they do not control, bitcoin is going to give true freedom to people and that is what they fear more than anything.
The impact of crypto currency is on the all paper currency because paper currency does not give some unique qualities that crypto currency provide such as; the high value pumps of the bitcoin, the high market value of the bitcoin and the most important one is the high security of the bitcoin. Also the easy transfer of the crypto currency and cheap rate for transfer. These qualities make people bound to use bitcoin which directly impact paper currency. The impact on paper currency directly impact the banks trade all over the world.