I know plenty of straight women who are
not content living their asexual lifestyle.
My theory is that this dynamic is mostly narrative-based, but partly physical:
Our social narrative says that a man's sexuality is dangerous, and that a woman's sexuality is fragile. It also says that safety comes from commitment.
The physical difference (that applies to sexual intercourse) between cis men and cis women is genitalia. The penis is homologous to the clitoris, and the vagina is homologous to the prostate. When a cis man has sex, he probably uses his penis, but when a cis woman has sex, she probably uses her vagina.
Most people who have mastered prostate stimulation can tell you it requires a completely different mental approach (headspace) than penis stimulation. This rules out most cis men, to whom the prostate is usually on a spectrum from unfamiliar to taboo: that gives queer/gay/trans people kind of opportunity advantage.
The headspace I'm talking about here is more of a yearning for connection (to connect with the prostate/vagina), as opposed to feeling impressed with and excited by someone's figure (to connect with the penis/clitoris).
The feeling of safety and commitment that can be found in a monogamous relationship is a really effective way to get into that headspace. This means that the utility of a committed romance can be directly applied to a cis woman's sexual experience, in the same way porn can be applied to a cis man's experience. This is where goals can be misaligned categorically along the boundary of sex.