For some what a character is wearing may seem superficial and insignificant however, I think what a character wears can communicate a lot of things such as time period, what they feel and it can easily show if a character is going through a transition in their life.
To illustrate this, I am going to give examples from the 2019 HBO show Euphoria. Euphoria follows the life of Rue a teenager who is a recovering drug addict as she narrates the story of her and some of her friends and their struggles in life. Euphoria is a very stylized show where all the stylistic choices possess a meaning especially what the character wear.
The outfits in the show can even be used to progress the story for instance in episode four Maddy is shamed for her outfit choice by her boyfriend who tells her she looks like a “hooker” which then causes her to take drugs and humiliate him in front of his whole family which then causes him to lash out and physically abuse Maddy. This shows the impact an outfit can have on the plot. The outfit choices also say a lot about the characters as a whole as Maddys choice show that she is confident and does not care what others think.
Moreover, another character’s outfits and appearance are used to visually show a change in her mindset and behaviour. In the first episode Kat is shown wearing plain clothing due the insecurity with her weight however, as the season progresses, she gains more self-confidence through her sexuality and is shown to wear more bold and daring outfits with materials such as leather and latex. This change in appearance is important as it causes the characters in the show to treat her differently and the plot would not have worked as well if they did not visually display her change as well.

In conclusion, I think that fashion and clothing can impact a story greatly when utilised correctly and can be just as important part of a character as what they say.