Bank is very important and its wrong to say that you shouldn't trust banks its so important to bitcoin cash out as exchange. Banking is very popular to people and being recognized by government as the safest storage of peoples saving as well as thier assets. Many business rely on banks and they are growing bigger as economy rises progressively.
well at the moment as bitcoin is not accepted in the whole world still by everyone, we still need banks, but in the future when bitcoin might potentially replace all the currencies we have we will not need any banks.
Bitcoin will not replace any of the existing currencies. Not sure why you even mention that. Bitcoin is purely here to serve people as an alternative form of conducting payments - instant money remittances - investment solution - store of wealth solution. No matter how much banks are despised by certain people here, you can't say that they don't play an important role in the economy at benefit of the user. I personally have a good relationship with my bank as they seem to take customer service very seriously. Never had any issues.