I think every one has to answer that for themselves. One person's reason might or might not fit another's situation. I have personally never subscribed to that whole "it's only paper" thing. Marriage means something to me. Being married is important to me. I didn't want to get a divorce, but that is where I landed, so I had to roll with it. My intention and one of the reasons I waited so long the first time to get married was that I fully intended to be married to that person until one of us was no longer here. But life happens and I realize that is a bit of a Pollyanna outlook. It doesn't work for everyone. Sure, some people do believe marriage is just a piece of paper and, likely, those people are just as committed to their relationship as some people who are legally married are. I'm not judging those people...their marriage or lack thereof is absolutely none of my business. Sparky's previous relationship was a living together but not legally married situation, but Sparky, like me, is the marrying kind and he wanted to marry his XGF, but she didn't "believe in marriage" so she wouldn't legally marry him. So, I guess we fit well. We can hang out, hook up and have fun and still be legally married.
I liked being a wife. I like being a girlfriend, but I like being a wife even more. I really don't know how to explain it...not sure if it is the old-fashioned part of me or what, but I want that "only paper". I want his last name. I want to say "this is my husband" and know that he is telling people I am his wife. It isn't a sense of ownership so much as a sense of pride that we are a team and we belong together. But, like I said in the beginning, that is MY thoughts and feelings, and fortunately, Sparky is in total agreement with me and we are on the same page. Not everyone feels that way and they have to make the right choice for them.
Me 52, H53 Bomb drop 9/29/2014 Divorce from XH final 12/17/2014 Marriage #2 12/31/2019 5 adult (step)daughters (3 from XH's first marriage, 2 from current H's previous relationships) 6 grandkids