I don't think it needs to have any value or meaning.
What is the meaning in, say, receiving a diploma/degree? I've never once looked back and thought, boy, I'm sure glad I have that piece of paper. The education I received remains with or without it. The recognition means absolutely nothing. It is really just an excuse to celebrate something going on in your life.
- I'm just arguing that marriage was meant to (in culture, religion) be different.
There seems to be two schools on this matter:
1. It was once traditionally illegal for mixed-race couples to be together, and marriage provided a licence from the state to allow those relationships on a case-by-case basis.
2. Alternatively, women were once thought to be the inferior gender and were pressured to bend to the wishes of their husband, and the marriage license made that control legally binding to a single entity.
Neither are socially acceptable anymore, thus any historical usage of marriage has been lost.