I think in general, women are more accepting of physical imperfection than men. Men are more visually focused and women a little more (definitely not totally) into a man's personality. Beauty standards for women are much harsher than for men. The acceptance of the dad bod, for example.
So possibly, for the shorter, less obviously attractive lad of 20, maybe his picking of women is slim. But by 30, if he is a genuinely good guy (and not the stereotypical incel 'nice guy' who is anything but) he should be able to have a relationship.
Also, as @notanotherone22 said, things definitely ARE changing. The old dynamic of the man being the breadwinner and the wife carrying the domestic load has changed. Women now frequently share the financial responsibility whereas men mostly do not contribute 50% to domestic/child labour. I don't know any married couple where it's 50/50. Not even when the woman out earns the man. Even 20 years ago when I was married, I wasn't prepared to accept carrying the housework/childcare alone. Not when I earned as much as him.
I also definitely accept it is quite possible for women to be shit mothers. I was not an earth mother by any stretch of the imagination. But the unalterable fact is, if a woman wants a child as a single person it is easily doable. Much, much less so for a man.
The great thing about being older is to be able to watch social movement as an observer, rather than living it.