Toxic masculinity describes something real - the propensity of some men to take what can be positive traits (stoicism, competitiveness, ambition) to an extreme where it becomes harmful to themselves and those around them.
However, I take issue with much of the conversation around “toxic masculinity”. While it is put forward as an unfortunate side effect of the gender which afflicts some it is then treated as an annoyance or an aggression. Those who demonstrate overly maladaptive masculine traits are not given sympathy or help, but the label is applied to them in a similar manner to how some “compassionate” people call Donald Trump mentally ill. It’s effectively an insult packaged in a diagnosis.