Since the CDC measures the number of divorces against the total US population, the number seems lower than the actual number of marriages ending in divorce.
The most obvious reason you need a prenup is to protect your assets. And it is especially true if one of you is entering the relationship owning more things than the other.
Adds an Element of RomanceA prenup can add an element of romance to a relationship because it forces you to discuss with the person you are interested in before things get too serious.
Sets Expectations
Even in relationships where everything is going great, a prenup can be beneficial by creating shared expectations. For example, it helps couples set expectations for joint accounts to pay bills.