So “marriage” doesn’t exist at all?
Marriage is a concept, not a physical object. Different cultures define it differently. Are you allowed to choose your partner, or must others do that for you? Does one family owe anything to the other, and if so, what? Can the relationship be terminated, and if so why and how? Does one party to the relationship have either rights or duties the other does not, and if so, what? What's the minimum age at which can a marriage rightfully/legally be consummated? Is it valid if the wife is not a virgin? Can the state control who may or may not be married? To be valid, must the ceremony be performed by a state official, or by a religious official? Is it still "marriage" if the required official doesn't perform the ceremony?