"Toxic masculinity" is actually a pro-men idea.

Men have a higher suicide rate than women. It is because there are very few ways to express "manness", and many aspects of masculinity have been deformed into things that are measurably damaging to someone's well-being. The fix is to celebrate a wide variety of incarnations of masculinity (from competitive jock to sensitive poet), while encouraging positive psychological behaviors that certain hypermasculine stereotypes discourage. It's not masculinity that is bad, but the rigidity and forced emotionlessness of mainstream masculinity that is.

When someone talks about toxic masculinity, they are being pro-men.

(This hypermasculinity also leads to sexism and sexual abuse, homophobia, transphobia, etc, but that is a different issue.)