Right now there is no such thing the can challange the banks. Their monopoly is just to strong.
Perhpas if some big wall street firms step in with bitcoin venture we can see this happeningMany people need some normal banks. Some people doesnt even know what Bitcoin is.
So how it is possible to make the banks disappear. First we must introduce Bitcoin to them and that it is maybe possible later in the future. Do you think so ?
I dont think we are going to see any kind of open defiance against banks, they are too powerful and will try to crush any competition the only reason they cannot crush bitcoin is for its decentralized nature.