Brilliant, I wish I’d thought of it.
It jibes with the hemline length/economic downturn theory (hedonism) and the Lipstick Index (comforts) and everything.
I would add that it’s a combination of male quality and low quantity.
e.g. 20s dress in response to new migrants (high occasional risk) and rowdy war veterans pissed off you stole their job during WW1.
e.g. late 40s, early 50s dress in response to rarity of males (low average risk) after WW2 and the whiteness of many towns and cities (within group quality). The men also made more of an effort to show the status of their bloodline and future/current household, to leverage in competition.