Like written before, they are fearing to loose their reason for existence. And they will not go down without a battle, like the video stores in the early 2000 did.
The reason they are fighting is because they are scared. While fighting the blockchain, they are working hard in the backroom to find a new business model, which will still give them power and control.
Don't forget that the biggest investors in for instance Facebook and investment funds and banks. They are shareholders in most every company who feels threatened by the blockchain.

It is a great indication how good cryptocurrency and the underlying blockchain technology is. If it weren't so great they would be still ignoring it.

But in the end, the banks will still be here. They probably will be the keeper of lost of wallets o something else.
It is an utopia that they will disappear, their power is just to bit for it. For sure they will loose power but still will keep existing!