The conventional marriage is quite possibly the worst way to show someone you love them.
Unconditional love makes marriage look primitive and restrictive in comparison. If the people getting married really loved each other that much, there’d be no need whatsoever to promise to stay together. They just would – because they want to. What more do you need?
Something along the lines of polyamory is a more ideal situation, even if you don’t find more than one person to be with. It’s the thought that counts – letting people be free, and not thinking you have some kind of right to demand that they not look at, talk to, hang out with or go out with anyone else.
If people get married and then years later realize they’re miserable together… there’s no point whatsoever in staying together anyway just ’cause they promised they would. I don’t think that’s “noble” or “courageous”… it’s cowardly. And mean. ‘Cause they’d probably both be happier and better off if they split up.
So, my conclusion is that marriage is unnecessary, but I am not totally opposed to the idea as a concept. It’s just been about as badly abused as the word “love” has. There is nothing wrong with two (or more!) people promising each other that they’re gonna stay together no matter what, as long as they were going to do that anyway and are not using the promise to force themselves to keep at it if they fear that someday they may change their minds and not want to anymore.