The issue really isn't with her character, because on paper she could actually be a very interesting character:>Former alcoholic superheroine with a whole host of mental issues related to her superheroics, known for her stubbornness and insistence on working according to the plan, is suddenly made one of the most powerful people in the universe, and now must juggle that responsibility with becoming an icon to the people of earth and an ambassador for earth to the various alien and cosmic powers that may seek to help or destroy them
The core issue is that Marvel didn't want that, they wanted her to be Marvel's equivalent of Wonder Woman and Superman rolled in to one. So they basically erase everything unique about Carol and make her in to a blank slate strong woman character.
Except even with this they can't be consistent with exactly what her personality is. Sometimes she's cool and assured of herself, sometimes she's a complete mess of anxiety and self-doubt. Sometimes she's the calm, collected voice of reason, sometimes she's an angry and brash idiot who just bashes things to death to fix the problem. Nobody really knows exactly *what* Carol is supposed to be.
And then there's the base issue that in spite of her colossally bad decision-making, she's never actually faced any consequences for her actions. I mean, she went full minority report, started arresting her close friends and associates, was culpable for the murder of at least one person, and personally tried to murder Tony Stark (only managing to not do so via technobabble nonsense), and she was punished by the President pinning a fucking medal on her chest and saying she was the best hero ever.