There seems to be a misconception of the dark phoenix saga in terms of female superheroes in Marvel. Why does this not surprise me. LOL
While maybe Marvel factually never had a seminar epic comic piece as impactful as the dark phoenix saga, what the story did do was give women more serious arcs and make them almost equal to men in the overall arching purpose of the story in team books.
I don't think many marvel females, especially on the X-MEN side such as Rogue, Storm, Kitty Pryde, Emma Frost to name a few would have have risen to prominence had it not been for the dark phoenix saga, I can argue those females became more important and more interesting for many comic writers to write (who are still mostly men) compared to their male love interest counterparts like Cyclops, Gambit, Colossus and even Wolverine.
I do remember reading books like Astonishing X-MEN and X-MEN Legacy in the 2000s, more than 20 years after the dark phoenix saga. Female characters such as Rogue, Kitty Pryde and Emma Frost were the stars of these books in a team that consists of Cyclops, Wolverine and Magneto. I don't think this would have happened if not for the Phoenix/ Dark Phoenix Saga.
In the 1960s, Stan Lee's Jean Grey was seen as useless, the weak link of the original 5 xmen members, however when Claremont did the dark phoenix saga, the women of marvel beyond X-MEN also began to get really good stories on their own without just been a weak link or a love interest.
There are many comic book experts that would even argue Days Of Future Past was the best Claremont work not the Dark Phoenix saga. DOFP was the story that gave Kitty Pryde high prominence and made Kitty a very well beloved comic book character.
X-MEN is very well known for their strong female cast and ushering in a new wave of feminism in comics.
https://comicsalliance.com/chris-cla...gue-jean-grey/
Mutant Women of Earth: How Chris Claremont Reinvented the Female Superhero
The women of marvel comics would be nothing if you remove many of the X-MEN female characters and none of that would have been possible had Jean not gotten that Phoenix story line.