There’s a very simple answer to this question, and it’s patriarchy. The patriarchy has still made sure that the society keep treating women as objects owned by men. By making them display their marital status on every document, the patriarchy just keeps on persisting the notion that women are nothing by themselves, they can only be seen in relation with men. If such was not the case, it would have been completely common for the men to be expected to display their marital status too. Instead it’s just the women who have been expected from the time unknown to display their marital status, be it in the title they use or their ornaments.