They are already uniting, as we have seen some news lately that involves cryptocurrency and the banks. Also, considering that XRP has really been trying to take the bold lead with being the centralized banker's coin, have completed some projects and possibly seeing some banks having interest may pose one of the reasons why banks will want to be a major part of this space.

Apart from that, we have heard in some countries and some companies coming up with cryptocurrency bank, which even though I know will only fly for the gullible ones, still shows that the banks are actually looking to be in the forefront. I believe it will be a symbiosis thing in the long run with banks and crypto space, uniting at least in a way, which I see banks trying to offer some services as well in the crypto space.