I don’t have the citations to back it up, but you get to the crux of it with shifting expectations of women. It feels (from all of the data I’ve consumed) like there is a shift away from needing a companion, marriage, or children for a substantial cohort of women (and instead, prioritization of self actualization, career, and more tenuous relationships in varying degrees), leading to a cohort of men who will be left without a partner. My hunch is that this is because it’s normalizing at a societal level (and a woman not following the traditional life script no longer carries the social penalty it once did).
I could accept women being unhappier in marriage than single, but I'm skeptical on the outcome being different for men than women without there being a very simple way for society to solve it.
The number one complaint I hear among women not wanting to get married / being picky is the potential future of requiring both a 0.6+FTE job and doing 30+ hours of housekeeping. That complaint is near universal among the developed world. Yet, there are plenty of men willing to share household duties, which in turn makes their number of hours spent "working" higher than before. Exactly the same situation as women. Yet somehow, the study would conclude something surpasses that for men to make them happier in marriage than women, while other studies tend to claim women are the ones who actively seek and value comfort and companionship more than men. That's not to mention child count going down and children used to be one of the biggest time / responsibility sinks.
All of that sounds rather fishy. It's not like men don't have their fair share of things to work through in a modern marriage, and bad picks can be, well, not picked. Especially today, with those traditional norms being removed.
