This is the case in my marriage, but not in my parents’. They are musicians, artists, perform together and/or take active stakes in each other’s careers. They weren’t sexual as I was growing up (I’m not giving intimate details here) but they had this whole other source of cohesion. A much greater one indeed — I have fond sexual memories but my parents have dozens of live albums at cool venues.

Then, maybe all of this anomie is a disease of affluence. The other thing that united my parents was that, well, they had to fight for survival and for the means if giving us kids a decent childhood experience. Maybe that alone works like continuous shared trauma, us-two-against-the-world.

That article says romance exists, not that it's the majority situation. Even leaving aside unromantic surviving marriages, the high divorce rate is strong evidence.

of course there are couples like that. OP was asking about the majority. is the majority like that? that study you linked doesn't seek to answer this question.

OP had a hunch and I provided something that wasn't just an opinion. If you then looked at the literature you could have pointed out that some research support an erosion theory of relationship satisfaction. I could have answered back that there is evidence that relationship satisfaction is a huge factor for relationship stability (who would have known), and stability should support relationship longevity. In the end we wouldn't be that much closer to a sure answer to the question, but we would all have learned something worthwhile about the topic.

It's a large and sprawling field of research. Why don't you dig into it yourself?