Banks will transform and find various ways to stay relevant. If they embrace crypto, they can easily start their own exchanges, enticing interests/benefits, and it will be the same again. If you ask me, the value of cryptocurrency is its use as the perfect currency for the internet. The internet is a lot bigger and older than crypto (crypto rides on the internet anyway) but I haven't known any industry it killed completely(e.g. traditional music, local TV, cable, movies). Like the internet, cryptocurrencies gives the us smaller people a bit more power/control than ever before.