What's the deal with women who just seem to enjoy hurting other women?

Women can be incredibly toxic. Some feminists love to push the concept of sisterhood, how all women should feel solidarity on the base of being the same group, etc. but reality is much more varied. I think some women and girls are really terrible when it comes to holding grudges, shaming others for example for not fitting the trends/what each clique considers cool and so on. Many women can present a false persona just for acceptance (this can be complex too, as a result of low self esteem but also on purpose), for gaining success and sacrificing various stuff. They can find some safe space among a chosen group and then become very loyal to them and attack anyone perceived as a threat or the opposite of said group - surely mostly in different ways than men may commonly attack, but still.

Part of me thinks, no wonder some girls nowadays turn to non-binary or transmasc identities. They are not strong enough yet to find their happy niche to thrive and make something meaningful out of their life, so the pain they endure due to social ostracism (sometimes combined with family issues) causes them to think “womanhood is a burden, girls are less powerful/less valuable/perpetual victims etc.”. Therefore they feel like choosing another identity is a way to regain control over life and dignity. What’s tragic, while the fake positivity of modern feminism and other movements is masking the real problems, there’s also a new factor - the acceptance of the harm that comes with transness, validating these delusions as “their choice”, “their real self”. With anorexia problem, no one (except the proana community) was accepting the harm they do to themselves. With transness, it’s expected to validate that.

So, in short, yeah many women sadly love to hurt other women of various reasons.