I don't think that bitcoin has the potential to make banks disappear or even make banks useless . the government especially those elites wouldn't want it to happen even if they already have the control in bitcoin .
It's not even something to debate as we are only hoping for the impossible to happen. Banks produce fiat and it's like saying bitcoin will replace fiat. Let's be practical here I guess, bitcoin is new and still on it's early stage and there's so much to prove in the future.
The world is control by the government and no government would allow a decentralized system where they losses their power.