Well, banks would still take from people as much as they can. They will force governments to regulate btc, this would make the currency just another asset they can control. End of story.
Yes the revaluation of the bitcoin will get in the world and this is the reason why the value and the price of the bitcoin is increasing more and more I hope this is the time to make the banks accept the bitcoin and to hold for the best time I can see how fast the bitcoin growth and the power increasing, the banks are good to keep the money but this is not going the benefit as it cannot increase the value and the price.
Yes banks would not get affected in any way due to the use of digital currencies because even now they are used at the highest possible scales in all the financial matters and even in todays world the whole of the economic growth whether it is about the local transactions or international relations.
Even now many of the people trust banks and keep their money in the accounts rather than using digital assets only due to the lack of confidence on the stability of digital assets.
I think nothing will happen to banks, banks will function in the same way as working now in the future also, but the number of customers may decline as digital revolution happening. Fiat currency is the legal currency issued by the bank officials, people are still dependent on fiat currency in many countries, So banks will remain in future also.