Banks got too much influence to dissapear. They are on the sidelines fighting to stop bitcoin's trend. First claiming bitcoin as their enemy but now launching their own blockchain solutions. So yeah with them being so influential I doubt bitcoin can make them dissapear.
Banks are now getting scared that they have a threat and they can see it to bitcoins. And if they aren't going do something about it for sure many clients of the banks are going to shift into using bitcoins. But the chance of making banks disappear by bitcoin is not going to happen. Because the government is not going to allow that.
If banks are scared about Bitcoin, you already know what they wanna do, right?
They will create a altcoin and put the world in the pocket, that's all.
And yeah, governments can ban Bitcoin.