Also, just found out something interesting which might further explain the attire of various characters in this game.

Originally Posted by
FFWikia
Tetsuya Nomura would be the director and character designer, but not costume designer, as Square Enix signed a contract with Japanese fashion brand "Roen" to promote their clothing designs in the game through different characters. Roen Creative Director Himuro Takahara serves as the game's costume designer.

I guess we should expect fashionable costumes for fashion stores and nothing but fashionable costumes for fashion stores. I expect with the limited number of females that pretty much every female will be dressed by Roen.