I don’t think it even matters. People don’t want woman led movies or action films right now. It’s just the Era. And to be honest I think Marvel is the one who started this with the mediocre Captain Marvel and have lost the trust of fans.
Captain Marvel is one of those few films that prompt me to reach out to Rotten Tomatoes and Metacritic--just to see if I generally agree with the opinions of paid critics, moviegoers, or neither.
CM is one where I slide towards paid critics' consensus.
It's not a great movie and did receive a notable recency boost from
Avengers: Infinity War. The latter, along with it having a decent level entertainment value, paid off at the box office. Although she does the Kree uniform justice, Brie Larson is NOT a fan favorite of a good percentage of the MCU audience. The lead actress was not enough to ding its overall appeal.
These are just my singular thoughts concerning a 'mediocre Captain Marvel' and mine alone. In my opinion, it is not so much a loss of trust for how portions of the audience reacted to
CM (or perhaps even
Wonder Woman to a lesser degree), but more so of lackluster movie making and superhero fatigue. I hold that view believe there would not have been a chance in hell of
CM remotely hitting $1 billion even with it coasting within the wake of
A:IW IF the main criteria was a lead actress headlining it instead of a male lead.
I think it is mostly a matter of moviegoers feeling any particular movie is good and have tired of the same formula (superhero-ing) getting tossed at them. I do not support it being a certain era phenomenon also. Case in point:
Superman: The Movie comes out in 1978. It is a hit with audiences, but does not gross half of
Star Wars: A New Hope box office. 1980's
Superman II sequel was another hit that did not gross as much as its predecessor. The wishy-washy Salkind producers had pretty much played out their corny movie-making streak BUT got Superman III green lit anyway for 1983. The box office magic of poorly financed movies had officially ran its course BUT nope.
They heaved a base cheap Supergirl out in 1984. Even Peter O'Toole and Faye Dunaway could not save that crap, much less a fresh-faced Helen Slater (hopefully I got the name right this time
@Runwildboys lol). That sucker bombed and bombed hard. Bad direction. Bad acting (even with film legends). Bad cinematography. Bad script. You name it. The original movie was the package deal. Plus, folks were generally Suped out within a ten-year period.
Sorry. My longwindedness is out of control. Just saying, that was forty years ago. Similar factors then are playing out in the here-and-now. One main element that is different now than then is unfettered criticism before, during, and after a movie's release. Literally nothing is out of bounds.
"CHA-KA!!!!!!!" 
People are and can be relentless.
Me? I will remain cool about all of it. My comic book nerdiness will never be sated UNLESS producers like the Salkinds take over. That would likely kill my appreciation of all these comic books and characters coming to live.