[barumi]

> On the other hand, with marriage, it's generally (hopefully) safe to assume that both parties trust each other fully before entering into the agreement. Whether and how that plays out in practice is another story, but IME, very few people enter into marriage prepared for the case in which it ends.

Sounds to me you're describing the whole point of marriage as a contract, as it specifies the default set of conditions and requirements that are applied to both parties, and also the rights and obligations of both parties in case of a contract resolution and even breach of contract.

> This is why prenuptial agreements can sometimes be a touchy subject, since it breaks that assumption of complete trust.

Again, it sounds like you're describing the whole point of marriage as a contract, as its the original (and baseline) prenuptial agreement.