I've been doing reading on "responsive desire", which according to research, describes how a majority of women's libido operates.

In short, a woman who is like this will have frequent enthusiastic sex only at the start of a relationship, especially prior to cohabitation. Once the "new relationship energy" wears off, she no longer gets spontaneously aroused by her partner. If she continues to want sex at all, it's only with some kind of aid to overcome her lack of arousal: be it erotica, porn, scheduled sex (force herself to have sex and let her mental arousal catch up to her body), etc. It requires lots of proactive, consistent effort on the part of the woman to maintain sex with her partner and we all know how good the average human being is at that (not very).

Given that these aids most likely did not even exist during our evolutionary history, it makes me question just how feasible it is to impose covenants like marriage on a species that -- at least for the female half -- simply wasn't engineered for it. It really seems more likely to me that women would pair up and fuck long enough to get pregnant and then immediately lose interest in the father (who would then simply leave and seek a more willing female), until ovulation began again and a new surge of NRE and interest in a new mate, repeating the cycle over and over for maximum genetic diversity.

In any case, this "responsive desire" and its prevalence among women is something I don't feel the majority of either men OR women are clued into. I almost feel that's by design, because how could you gyp men into committing to women if they knew they'd eventually have to grapple with this horrendous situation? That is, dealing with a wife who can just barely manage to want to fuck them, but still restricts their fucking other women. Whose libido will essentially become broken at some point, never to be resurrected except, perhaps, by the high provided by a novel adulterous/polyamorous partner.

I don't feel most sane men would sign up for that if they knew that was how it would play out. I feel like this information, if fully processed by society, is a death knell for marriage. It would shatter marriage, possibly even cohabitation and monogamous LTRs, if it was understood just how divergent male and female sex drives are over the long term.

Also, just to try to anticipate some likely responses:

But I'm female and am not like this / my partner is female and isn't like this!

The research points to this being the norm among women, if you are an outlier, feel free to count your blessings, but it doesn't really impact the crux of my argument.

You can overcome this by being alpha enough. Just be alpha bro.

Not feasible for the majority of men. 20% in a best case scenario (pareto principle). Again, doesn't really address the crux of my argument.

Men suck too! They're hardwired to fuck the waitress.

Not disputing that, if anything it reinforces my belief that the current set up is unnatural and perhaps should, and likely will, be replaced by something else over the long term.

The blissfully ignorant beliefs that undergird monogamy can't stand up forever against the scrutiny of investigative science. Marriage contracts may have made sense during the heyday of patriarchy when all wealth was tied to land and inheritance and so on and forming familial alliances was crucial... but I don't see much utility in them anymore.

One counterargument I admit has merit is, if women aren't wired for monogamy, then why do women cling to a relationship and commitment with a man even while their own sexual desire for that man is tanking? My answer: I think this has more to do with culture and rational self interest than sexuality. In an atomized world like ours you need two partners busting their humps to provide a "decent" life and to raise children, preferably with familial support on both sides. It is the potential loss of support that women fear in this scenario, not the loss of the individual man, I posit.

By contrast, in our evolutionary past, this fear wouldn't have existed: you'd have a whole clan of people all supporting each other and raising kids communally, and splitting from your partner wouldn't carry the same loss of status, stigma, and financial strain that it presently does.