I don’t think that’s really true in general. While the Captain Marvel comics may not have been that popular, AFAICT, She-Hulk and Wonder Woman have always been popular characters and they seem to me to fit the definition of girl-boss just as well as Captain Marvel.
But I agree with you that
And I will go even farther and say that, at least in western media, it’s hard to find stories with a male MC/protagonist who is softer/more feminine than (the male) average, where a) he isn’t (mainly) a victim b) this isn’t (mainly) played for laughs or c) the writers or other creators of the media overcompensates for making him softer and more feminine than average and make him physically powerful, a great fighter, give him plenty of traditional masculine virtues as well or in other ways seemingly try to water down him being softer and more feminine as much as possible.
And just like there are girls and women out there who are tougher and more assertive and should get representation and possible role models, there are certainly also guys out there who are softer than average and should get both more representation and possible role models instead of de facto being told by the stories to toughen up and that you will be victim or a figure of fun unless you know how to fight and/or are physically powerful.
To give you one example from a particular media and genre: I’ve read a lot of fantasy books and series. But while the proportion of MCs who aren’t big, strong, male warrior heroes has increased, there are still not that many male MCs who succeed mainly through their softer qualities, such as kindness,compassion, listening to other people and maybe also healing magic. Yes, the number of trickster MCs(including male ones), who are neither physically powerful nor particularly good at fighting has certainly increased, which I think is a good thing. But the number of male MCs who are softer than average and where they are neither mainly a victim, a figure of fun or have so many traditionally masculine qualities or warrior MC skills and attributes that their softer qualities are watered down in a major way is still really low. I would have liked to see more male fantasy MCs who are like Skeeve in the Myth series, who succeeds through caring about his friends and other people he meets, seeing the best in other people and thinking outside the box rather than being physically corageous,assertive and good at fighting. But that’s a kind of MC that still seems to be quite rare,unfortunately. From what I can see,(western) comics, tv series and movies don’t really seem to be that much better and I can’t really think of a current western media and genre where things are that much better, tbh.
There have been women here earlier complaining that there aren’t enough heroines who are heroines precisely because of softer and more traditionally feminine qualities. But there are even fewer male heroes who are like that, so I do suspect there is a kind of general prejudice among many writers and other media creators that say that a hero can’t be too soft. Which in turn may be connected to how many genres tend to have their happy endings come about through violence. For some genres, like action I can understand it and see that it would probably be hard to imagine stories made in that genre where violence wasn’t an essential part. But for other genres, like fantasy for instance, there’s really nothing essential about the heroes getting their happy ending through the use of violence and it would be interesting to see more writers exploring other ways of resolving their stories. Don’t get me wrong, though, I’m not saying that violence should never be an important part of the plot and resolution in fantasy stories, but I am saying that it would be nice if the proportion of fantasy stories that didn’t get their resolution through the use would be greater than it is now. This is actually one area where I think regular COGs have often been quite good, since it is actually quite often possible to get a nice ending without using violence, at least compared to stories that aren’t interactive.