
To be fair to the FL, just like the ML needs clothes and equipment to maintain a status quo, so too does the FL need dresses & outfits to maintain her position as a 'duchess' in high society.
It's definitely silly, but it's also essential to positively engage with the nobility.
(I know. I know. It's not that deep -.-)
And it's part of the 'she's so different' trope (︶︿︶)
I just dislike when MLs and those who identify as men in general act like a FL or person identifying as women is 'frivolous' if they're interested in fashion.
...As if them buying swords and suits is cheap )