Serious, dark, extremely violent, acting is high quality. There are some parts that are fairly bad, but nothing that isn't par for the course in a Marvel movie over the last 10 years. One section drags monotonously long to convey a "family reunion," & the finale climax is somehow more over-the-top than some Avengers climaxes. Beyond unbelievable, but this is Marvel (steadily declining).
IMDb & Rotten Tomatoes have become so irrelevant to movie ratings it's not even funny. This film has the same Rotten Tomatoes rating (80% critic) as She Hulk Attorney at law. There is no valid reason for a show like She Hulk to exist, it's so mind-blowingly garbage it's insulting to Marvel as a whole. Google reviews are far more accurate to public ratings. So overall, Black Widow is a solid 4-star film in today's era. She deserved this film 6 years ago.