I think tznius is actually a woman’s mitzva to protect the woman from being seen as a mere object, “eye candy” for men.
Woman can and should dress in a respectable manner, but shouldn’t be reduced as mere skin to be shown. Frum girls don’t understand this because they are not exposed to general socializing with men, but nebach these poor girls and women who have to compete and vie for men’s attention.
Woman who are dressed b’tznius, but beautiful have a chein that is sorely lacking in those frum girls who try to push the parameters of tznius boundries. Neutral makeup that enhance the features are so much more becoming than clown makeup. A nice skirt that’s not too long to look schluchy but also covers the knee when sitting (a line skirts are cute and very tzniusdig) is more elegant than a short skirt that barely touches the knee. Tight clothing is cheapy looking, while clothing that’s not baggy, but just the right fit shows a refined taste.
Tznius is self respect. That doesn’t mean that a girl that doesn’t dress b’tznius doesn’t have self esteem. It just means that she does not have the self respect not to dress in a flaunting manner.
As I mentioned above, I don’t think tznius is a mitzva only to protect the men. The woman goyim today (shiksa today is not a politically correct word) are actually walking around undressed. So why shouldn’t frum woman too? After all were we women only to dress this way because of how it affects the men, then there is no pshat of being dressed tzniusdig if men can see other women barely dressed.
Tznius is a gift that Hashem has given us so that we will not be reduced to mere objects. This mitzva allows us women to present and conduct ourselves with dignity and pride of being a bas Yisroel.