What is the Point of Saving Sex till Marriage?

One day she asked me with such a worried look on her face—“is it really worth it to wait to have sex after marriage?” I gasped for some air, already calculating what answer I was going to give her when she interjected my thoughts by saying; “I look at my mother’s marriage today, and if that is all marriage has to offer, I want no part in it. She is a devout Christian, did everything right, was a virgin until she got married, prides herself in able to keep her legs closed all those years, but yet she isn’t happy; I see it in her eyes. What is the point of saving sex till marriage?”