Why get married?

What is the reason for getting married? I have been thinking about it a lot recently. I am at a close friend's wedding and just can't figure out why I would want to do this. I have a partner that I love and want to spend my life with. We have a house (with a cohabitation agreement serving as a "prenup but for a house") and do not want children. We love each other but don't understand why we would have a wedding and a marriage license

What is the reason you decided to get married? What am I not seeing?

I picture myself in the bride and groom's shoes, and both perspectives seem bad to me. I assume I don't get this because of autism and queerness. I would love answers or even just a discussion in the comments

Thank you all in advance for the community you have created.