Cohabitation/having a family the equivalent of being married?

So I’m curious... it seems to me (at least where I live), that more and more people are choosing to co-habitate and have children together but don’t choose to get married, which got me thinking...

Do you think living with your SO and having a family together is just as “official” (I wish I could think of a better term than that - please feel free to offer up something else!) as being married to one another?

I personally am proud to be a wife for various reasons, and although to some it’s just a piece of paper, to me that paper helps to signify our commitment to one another and helps define my husband and I as being a family outside of our individual families that we came from. However, I understand that marriage is not for everyone, and that doesn’t make them less of a “family” for not being married.

I would love to hear other’s opinions!