The risk of marriage is what makes the commitment meaningful. Of course, you can always substitute for marriage with other forms of commitment in partnerships, marriage is just a particular choice.
In your writing, however, it rather appears to me that you do not see the value in committing to another person at all - in whatever shape or form.
In that case, I would say that the desire for marriage is likely to remain an enigma to you.
In rational terms, consider marriage (or another form of commitment) as a dynamic non cooperative game where a long term mutually beneficial equilibrium is reached.
Briefly, imagine you meet another person to whom you actually want to commit to: you derive utility from demonstrating vulnerability under risk.
This is the case, because the other person similarly commits to you. This mutual equilibrium is only possible with mutual trust. In turn, trust in the other person grows with mutual commitment. Trust is the driver of non ego behavior, shared understanding, and sensemaking. For evolutionary reasons, it also leads to a feeling of safety and reduces the impact of many day to day stressors. Of course, trust is only built up if the demonstrated commitment occurs under real risk and increases then over time, where the initial jump however determines largely the final equilibrium.
The equilibrium is high utility not only due to the feeling of safety and partnership, but also because a high trust environment removes transaction costs.
In turn, commitment is higher in value if the choice to deviate is meaningful, if the risk is real, if your money and income aren’t safe. If you jumped, and your partner equally jumped, both without knowing with certainty. Thus demonstrated commitment leads to a higher utility equilibrium as outlined above.
I hope this game theoretic analysis indicates to you some benefits of something like marriage.
Having lived both extremely independently and married, I strongly believe that my marriage equilibrium is far superior.
I also know that trying to get the same benefits without commitment, that is, without taking an inherent risk on another person, would not lead to the same outcome.
After all, without risk, its not really meaningful.
While marriage is just one form, I strongly believe to know that today’s culture of risk aversion in partnership leads to lower utility and long term happiness.
People are afraid to lose or give anything up.
In turn, they will gain less.
I acknowledge fully that I would not have understood the above before my marriage.