> Females have a biological incentive to be more choosy than men as their reproductive investment is much higher
until I saw you had also written
> If each woman and each man can only choose one partner, i would expect the choosiness of men and women to become much more equal
which is the missing piece I was going to add.
> In reality we know that humans historically have not really been monogamous creatures, even in societies that are nominally so.
But, to shift emphasis a little, in those societies, many many people really were monogamous, there absolutely were, and are, functioning lifelong pair-bonds, there were men who devoted a lot of themselves to being good husbands and fathers, and, I'd like to think, there still can be. But yes, such men will need to be choosy, because they're making the biggest investment of their lives.