maybe one day in the future... but today too many people don't know about bitcoin & old people don't want hear nothing about new payment methods, so I think that 50 years min.
Unless there will be some form of war or calamities where there will be chaos and everything, maybe - and only maybe that it will make the bank disappear. But to be honest, I am doubtful that it will really disappear banks. Bitcoin is a good form of investment and other side method to earn money for our family needs and wants. Hopefully, everyone takes advantage of the recent bitcoin price rising.