Masculinity and Femininity are a partially socially-constructed, partially biological phenomenon.
Essentially, gendered trait distribution resembles two overlapping bell curves, controlled by hormonal levels at key points in development, along with genes, epigenetics, and environmental factors.
Pre-natal testosterone levels - in females, not just males - track with later toy preferences for mechanical/systems toys vs social ones. While the effects of sex hormones are not simple, they are very much not a placebo.
Society then layers its gender roles on top of this, driven in part by previous economies and incentives that may no longer exist. Often it exaggerates, or essentializes, and so for this reason people go “well dresses are obviously not biological and not all people like the assigned roles, therefore male and female are exactly the same and all apparent differences are caused by societal brainwashing.”
So we might think of masculine/feminine as the axis of opposition for gendered traits. (Intelligence does not appear to be one of these traits, as the center point seems to be the same.) Alternatively, we might think of it as the center points of the respective bell curves.
It’s important to remember, however, that the masculine woman and the feminine man are both legitimate, as well as various other mixes on more than one trait. Humans are complicated and biology is quite noisy and also complicated. But the clustering is still real.
The issue with your plan is that cishets seem to actually want someone who differs on the gender axes from them in that masc/femme way in terms of their attraction (which they don’t consciously control), and the idea that we’ll abolish gender and not have them identify as the labeled gender clumps associated with their respective sexes (cishets in specific) in the name of some modern idea of liberation… well I’m confident that won’t work out very well.