I think neatness is important perhaps it shows some respect.
I went to a church years ago, and there were young girls (round about my age) in low cut tops and jeans. Needless to say, as a red-blooded male, it was difficult for me to keep my mind on spiritual things.
The women in our ward get to wear pretty much anything as long as it’s modest, and uses a skirt. (One girl turns up occasionally in jeans, but this is discouraged. Some of the female investigators do as well, but otherwise the women wear a far wider range of stuff than we do.)
White shirts… are a pain. I am not good at washing clothes, and they tend to stain easily with anything and everything… food, mud, drink, stuff you’re carrying etc.