In addition to security and speed, SWIFT offers a standard interface to reach pretty much any bank in the world with a standard message format to provide completely automated processing of payments, straight-through processing (STP) in industry terminology.
In finance, standards can take years to define as working groups from banks, securities firms and depositories meet repeatedly to hash out what needs to be in a message and ways to make it machine-readable so the communication can be handled by computers with straight-through processing (STP) and not require any expensive, time-consuming and error-inducing human intervention.