Will banks fold if they don't adopt crypto currencies. I think as important and sensitive as this question is, I don't really thinks that banks will fold if they don't adopt crypto currencies because while bitcoins are digital and decentralized, banks deals with hard currencies like the united states' uses the USD in their Banks and so long as the USD is in use the banks will still operate, because they will be there to do the day to day transactions of the United States Of America. Though the activities can be reduced if Bitcoin is accepted beyond what it is now.
Even though the frequency of transactions in conventional banks decreases due to the adoption of Bitcoin, I don't think it will make banks extinct. I agree that banks and Bitcoin can go hand in hand. One of the advantages of Bitcoin is that it is decentralized, and can make transactions in any amount and without any borders between countries. But on the other hand, I think the use of paper money or digital-based fiat money will not be extinct in the next 10 years. And for daily transactions such as shopping or small transactions, I think Bitcoin is still not the first choice.