It exists because banks need a way to know that money is coming to them, it more or less balances books. You are right, a Swiss bank could just call a Russian b

It exists because banks need a way to know that money is coming to them, it more or less balances books. You are right, a Swiss bank could just call a Russian bank and say “hey we are sending you this money”, but A it would be a pain in the ass, and B, they could risk getting in trouble, but they are Swiss so they can do what they want hahaha.