No bitcoin can't make banks dissapear. Physical banks can dissapear, yes that's true but bitcoin won't be the reason that this will happen.
You're still going to need fiat if you're country hasn't adapted to bitcoin yet, so you will always need to exchange.
Yeah, bitcoin will be more powerful in future, but it cannot make banks disappear, as the majority of the population is dependent of banks and they would never choose bitcoins over the banks.