In particular with regarding things like attractiveness and success. These things cause a lot of resentment. It seems like the female solidarity you see in many online spaces is just a facade. In reality women are very competitive with each other. Like if a woman sees a more attractive woman getting attention from men rather than her. This makes her VERY angry. This is also mostly hidden from men. Interactions with men tend be courteous by and large. Interactions between women in private tend to be more catty. I'm not making this up either. A female friend told me this is how it usually goes.