As a fan of Captain Marvel and Ms. Marvel I too think the trailers make the movie look like a fun romp but I can see why it's not generating the excitement that it should.
The villain is completely unknown (I checked, the character appeared in a total of 3 issues in the early 90s) and visually she doesn't look particularly interesting. On top of that it's your typical "the villain wants revenge" plot. Fans get just as excited about seeing their favourite villains as they do about seeing their favourite heroes. Ultron, Hela, Thanos and Kang (heck, even Gorr) all generated considerable buzz among fans before the movies came out. But they're not getting that here.
In hindsight I think it's a shame Ronan was killed off in the first Guardians flick because Lee Pace is a great actor and could play that character really well (just see his performance in Foundation) if he was provided with good material. We get a small hint of what Pace could have done with the character in this brief scene.
So I think the trailers ultimately fail to sell a conflict that fans could get invested in.