Banks are still important in the world, we cannot just say that it is better to close because there are some cryptocurrency exchanges. Banks are used for traditional transactions and we all know that cryptocurrency is not that ready to use instead of using banks because cryptocurrency still needs to be innovated and become recognized by all countries as well. We can say that there are still countries that are prohibiting the usage of cryptocurrency and that is not good for everyone if they try to close the banks. Also, the knowledge about cryptocurrency is not known by all people, so it is hard to do a quick change.
It is retarded to say that cryptocurrency exchanges will replace banks. We need banks to deal with currency. Bitcoin on the other hand, is an investment asset and not a currency. You can compare cryptocurrency exchanges with stock markets, but not with banks. Banks are an integral part of the modern economic and financial system, and they will survive as long as humanity exists on this planet.