Well, if you do that with 3 parties A, B and C. You have to trust everyone with access to exchange funds that they won't cooperate against you. With blockchain

Well, if you do that with 3 parties A, B and C. You have to trust everyone with access to exchange funds that they won't cooperate against you. With blockchains, you can check if they're cooperating against you. You may even be able to prove it later in a court of law, which sounds useful. Another big plus seems to be that it replaces 1950s era systems in most countries that, at least partially, rely on humans in the transaction feed. They also require trust, and trust requires approval in these organisations (because it has been abused before, usually by the people now approving it, who are still abusing it, but that's beside the point). In order to avoid this banks have a ton of 1:1 relationships that are sometimes fully, sometimes partially automated and this can really be an n:n system if it's under the control of the central bank.