That's certainly true, mate. Banks will never go away simply because they're "too big to fail". Governments need them for the issuance and circulation of money, so such financial institutions will be relevant in the future even with crypto/Blockchain tech in play. What they will do is create digital currencies of their own to avoid being left behind in the dust.
The real reason why Banks hate Bitcoin it's because of its decentralized and censorship-resistant design. Not because it threatens the existence of Fiat. Bitcoin is freedom, while Fiat is slavery. Banks want you to play by their rules by being enslaved to a centralized monetary system that can easily be debased. The more people use Bitcoin, the more furious banks will get. This is will be a never-ending battle between crypto and Fiat. At least, we know Bitcoin won't be going anywhere soon. Who knows if it lives alongside Fiat for generations? Just my thoughts