I don't really understand the fear mongering going on here. It's not like if we decline past a certain level of marriages that all of a sudden marriages would go extinct. People who want to get married will still get married and people who don't, won't.

But I mean, even if they did, would we really be losing much anyway? Marriage has never quite made sense to me other than for tax purposes (which is a pretty cruddy reason to formalize being with someone forever imo)

It's always seemed super short sighted. People change. And you can't predict how they may change. Your partner that you love now could end up changing into someone you no longer love or worse. Committing to forever is just promising that you'll stay with them even if they make you profoundly unhappy. I've only got this one life to live. I'm not commiting all of it to someone I may not like being around later on.