As I understand it, "toxic masculinity" is otherwise healthy masculine traits taken to an unhealthy extreme. "Toxic femininity" would be the converse In other words, it's not just men or women behaving badly. I agree that "toxic masculinity" is now so inflammatory and unspecifically used that it is a useless term. "Toxic feminity" is regularly misused. Women behaving in a toxic fashion is not necessarily toxic femininity. I'm working on a story about that right now.