They were not always men's clothes either. Our Lord, and St Joseph didn't wear them.
But they did wear men's clothes. Not women's clothes. Trousers have been men's clothes, and remain men's clothes and not women's clothes, except among people who accept feminist fashions.
Cardinal Siri said they were not immodest!
Not all pants are immodest. Generally speaking women wear immodest pants. That's the reality of the world. Pants outline more, and generally speaking, they fit snugly around a womans waist, hips and upper legs. Generally speaking, walking down the street, women's pants are immodest.
...the wearing of men's trousers by women cannot be said to constitute as such a grave offence against modesty, because trousers certainly cover more of woman's body than do modern women's skirts.
Except Cardinal Siri is condemning pants, and he's also suggesting modern women's skirts are very bad as well.
I can't imagine why anyone is so supportive of fashions that come from the de-Christianizing of society.
I don't think a woman who wears pants is necessarily sinning, but, I think a woman who realizes that pants are less feminine, that the wearing of pants by women became common because of the de-Christianization of society and the advance of feminism, would ever wear pants except for rough work or possibly sports. Certainly never for social purposes.
Most women who wear pants are wearing immodest ones.