I think bank will still go on but i think they will adopt to crypto may be also day will make their own coins
Most likely, banks will simply give up the fiat and start using the cryptocurrency as a means of payment over time
Not most likely. Bank have a really huge chance of creating their own means of digital currency just like how credit and debit card works. Because of that cryptocurrency will have a hard time competing because people are already thinking that Bank is the place where they can store and do some transactions meanwhile there's better option out there.