NO. They will never replace banks as blockchain is designed to coexist with it. I don't see a point where they need to replace banks as they are still functional and blockchain is far from developing the same way as bank does. I think those people just fantasizing things instead of facing the reality. Also, just want to mention that ICO's offering the same services as banks are the ones who were failing because we already have those services offered on crypto. REDUNDANT COIN.