My wife and I watched it last night (we're still not going to movies like we used to so we didn't go see it in the theaters) and we enjoyed it. There was something about it, however, that was different from most other MCU output. I don't think the direction had as much polish with the superhero action as Favreau or the Russo brothers (though, honestly, they left some pretty high bars). And I thought Zawe Ashton was kind of stiff as Dar-Benn. But the interplay between our primary heroes was really good and covered a lot of tonal shifts in emotion.
Overall, I thought it better than Ant-Man and the Wasp: Quantumania and maybe even Guardians of the Galaxy 3. The critical response was fine. So what, exactly, torpedoed it in the theaters, I'm not sure I fully understand. I don't think it's just backlash against Brie Larson because there was plenty of that in the run up to Captain Marvel and it still killed at the box office. I think superhero movies are underperforming in general due to uncertainty in their future stories (DC's meltdown and Jonathan Majors' legal implosion) and market saturation, but it's still an unusually weird drop off that I don't think antifeminist backlash can fully explain.