Bitcoin is the only one currency which is dealing people and people are coming attract to bitcoin because bitcoin is the only currency which having future well if we think about ETH then it is also quite good for future.
I do believe that banks from past years of old times really accepts only one currency, but as of todays modernization of banking technology, banks were more aware and accepting exchanges from digital to fiat currency. Sometimes it's getting redundant to read this questions so far, because bank will not be eliminated due to it's purpose is highly recognized by people around the world.