Today, banks clear transactions between themselves through the SWIFT network. By investing in distributed ledgers, a group of banks can collude to avoid settlement feees incurred by going through SWIFT.

That's the benefit to financial institutions, and the threat to SWIFT. The technology itself is nearly irrelevant. From a game theory perspective, what matters is whether their R&D is plausible enough that they can use the tech as leverage to negotiate lower fees.

Also known as cutting out the middleman.