As Internet and email destroyed work of post offices about letters sending as Bitcoin will destroy banks system about using money. That is my opinion. And I'm pretty Shute that it is going to be as u say - bitcoin or maybe any other of crypto currency will be used mostly by people.
The banks are not used to send money. They provide borrowing and lending service. With bitcoin, they will make more money.
You mean to say you cannot transfer money overseas from the banks? No mate you can send and receive money in the form of telegraphic transfers and wire transfers, but charges are too high.
The main benefit for using banks is to save and borrow for me. I rarely send money. But it is good to send money with bitcoin myself.