I mean you are correct in a way, but I would say there's a lot of focus on what men wear as well it's just...different. And it's not universal, it varies greatly from culture to culture based on an enormous number of variables. In the west women are usually expected to be modest, though this is not nearly as discussed as in the past. Men are expected to look professional or clean-cut or well kept. One of those. Again, also a very much faded thing. But at their height, both of these were taken very seriously, not just women's clothing. A woman couldn't show up wearing a revealing piece of clothing and a man would never dream of wearing jeans. It comes from an era of gilded morals really, where there was an over-emphasis on appearances vs what people were actually like.
And it also comes from the fact that, like it or not, face it or not, we all make snap judgments based on how people look. It's a natural, reflexive thing. Which is why we and society do put some degree of emphasis on appearances.