The shonen genre as a whole is primarily targeted at young boys. As a result, the characters celebrated the most were those its target audience was supposed to identify with and look up to; characters who fit into their demographic. Powerful female characters did exist but they were few and far between. A lot of progress has been made in female representation in animanga over the years, but a few unsavory tropes still persist in many popular shonen titles, including My Hero Academia.
In terms of strength at least, My Hero Academia's female Pro Heroes are about as evenly matched to their male counterparts. Mt. Lady proved as much when she foiled the League of Villains' attempt to foil Katsuki Bakugo's Kamino Incident escape. And who could forget her titanic wrestling match with Gigantomachia? More recently, Star and Stripe redefined the limits of what a Quirk battle could be and went toe to toe with MHA's big bad. These aren't frail women by any means and their strength makes it incredibly easy to notice their absence as the story moves on.
This year alone, My Hero Academia introduced two phenomenal female characters. Lady Nagant offered a back-door look at the inner workings of the Hero Safety Commission and challenged Izuku Midoriya's view of the Hero society once again. Star and Stripe quickly proved she was the closest thing the series currently had to All Might and may have severely crippled All For One during their battle. Both of them seemed to have much more to offer the series so it was quite a surprise that neither lasted for longer than a volume.
It was for good reason, of course. Both of them sustained injuries that would have raised eyebrows had been shown unharmed shortly after but their short-lived appearances aren't a unique phenomenon. Far too often, the women in My Hero Academia get side-lined after their first brush with action. It happened with Mirko after she defeated several High-End Nomu during the Paranormal Liberation War. Similarly, Midnight's brief showing in the war inexplicably ended with her death.
My Hero Academia has never glossed over the dangers associated with being a Pro Hero. The most important battles often end with many characters sporting serious injuries regardless of gender but the disparity arises in the aftermath of the battles. They often heal from their injuries and go right back to their previously established roles in the story. Characters like Gran Torino, Endeavor, and Eraserhead are some of the series' favorite punching bags and yet they're somehow always back on their feet. They're also heavily involved in the more strategic aspects of being a Pro Hero, establishing plans of attack and setting the rules of engagement with the enemy, a process the women characters are noticeably absent from.
My Hero Academia has a fine female cast, all with powerful Quirks and individual ideas of greatness. The problem many fans have with them is that they are underutilized and a lot of the time only serve to decorate the background. Of course, acknowledging their strength in battle is some form of empowerment on its own but for each of them to fully live up to their potential, they'll need a bit more exposition than that.
