When people in Britain suddenly started searching for sex toy discounts a little more than normal, Voucher Codes Pro decided to do a little research on people in long term relationships - namely, how they feel about their sex lives.
Surprisingly for some (and relieving for many others), when both genders were asked if they wished they were having more sex, substantially more women reported yes. How's that for obliterating the ol' my-wife-refuses-to-bang-me trope?
In all serious, though, we do live in a world that seems to think that women want sex in return for love or money - or that they're kind of "meh" about it in comparison to men at the very least. Though, yes, men certainly produce more testosterone than women do, all of the historical and anthropological history (as well as modern and past primate studies)... completely refute that notion. In fact, before the rise of private property, it was pretty widely accepted that women were the more sexual of the bunch.
Don't get me wrong - I'm not saying that men aren't horny buggers, because believe me, I know they are. But for all female sexuality is cracked up to be (a finicky, fickle Rubix cube of a thing), not very many stereotypes are supported by science. In fact, most women don't even know how sexual they are. Why, you ask? Repression, folks, can really fuck with your mind, and not in the fun way.
Journalist Daniel Bergner took a deep dive into female sexuality in his book “What Do Women Want?: Adventures in the Science of Female Desire,” which I have read and so should you. In it, he illuminates something that might scare the patooty out of hetero men far and wide: Anatomically and sexually speaking, women are actually even less suited for monogamy than men are.
That, of course, does not mean that women can't be monogamous or don't want to be - many men are quite happy in sexually exclusive relationships despite being told their biology is ill-suited for it. But you can see how the rewriting of female sexuality is based in a convenient fantasy, perpetuated by our own confirmation bias. Objectively, women are just as ravenous for sex as men are - at least they would be, had they been given permission from the beginning.
So, after all that, the answer to the question "Why do we think men want sex more than women?" is simply: Because that's how people have wanted it to be.