I work in Social Security and let me tell you, widows and widowers who can only get back on their feet after the death of a spouse thanks to benefits that they are entitled to due to marriage are a daily occurance. Sometimes, even the death of a spouse you DIVORCED. Also it provides a few interesting options to maximize your monthly check in the long term. Then of course there are other legal rights that come with marriage, which bear responsibilities that need to be in place to ensure that not just anyone can get benefits from you. Plus, entangling your lives in a marriage is a commitment device, and though not perfect, commitment devices can work and make you more dedicated to something that you truly want. If you don't want to commit in that way, that's your choice, and a valid one, but its important that you have that choice should you want it.