Unfortunately, not every man gives the Kesubah the respect it deserves.
I’m not saying that it’s true in every case of divorce;
but there are many Agunas whose husband won’t give them a divorce.
From the RCA website, prenup.org:
“In some cases, spouses have purposely withheld a Get even where their marriages have functionally ended. Some spouses have refused to participate in the Get process in order to extract concessions in divorce negotiations, in order to extort money, or simply out of spite.
Traditionally, rabbinical courts (Batei Din) have been charged with the responsibility of overseeing the process of Jewish divorce, and ensuring that Get is not improperly withheld. However, in modern society, Batei Din frequently lack the authority to do so. The Prenup is a document entered into by a man and woman prior to their marriage. It provides that in the unfortunate event of divorce, the Beit Din will have the proper authority to ensure that the Get is not used as a bargaining chip.”