I think I'm emotionally underdeveloped because of male gender norms. Specificly the norm that men are not emotional. It feels like my non-male friends run laps around me when it comes to navigating their/others emotions.
The harm of this deficiency it no doubt obvious to most. But it took me a long time to even recognize that it was a problem. The harm I've experienced from this is the damage I've done to my relationships throughout my life.
Caveat - I'm not sure how much responsibility societal pressures bear alone since my parents were not great emotional models.
Other then that, I think I've only benefited from gender norms.