For the record, I think its a cultural shift.
Back before the industrial revolution, marriage was a lot more a contract and a necessity for farm life. There was no convenience food. If a man was harvesting wheat, he needed someone to t urn it into bread. And he needed to create farm hands (kids) to help. He needed at least one woman for that.
Nowadays, those parameters aren’t quite the same. Romance is more of a cultural thing.