This guy knows. Of course you can get those another way, but marriage is the no questions asked route for most people.
Why do you think gay marriage is big news? Gays could always find ways around, but that's the point, marriage is easier and you need to jump through hoops to get the same thing, it's discriminatory and makes a difference between normal and not normal or acceptable ways of getting common ass rights and validations, absolutely useful for when you plan to spend more than a couple of years with someone.
Also, I think you confuse marriage with weddings, those are usually the expensive and stupid ones. Ceremonies are not required to be that stupid.
I wonder if a fediverse version of that would resonate with any of my friends and family. Seems like we are where we started with forums, just strangers respectfully taking about their common interests. Social media is indeed dead.