This is a Cap movie pretending to be Avengers, but expecting to perform like Avengers. If this movie fails to perform like Avengers, people will say it should perform like a Cap movie. However, how can a movie ( featuring Spidey, Iron Man, Black Panther, Ant-Man, Scarlet Witch, Hawkeye, Black Widow, Vision, War Machine ) perform like a "Cap movie"?
Besides, the budget is 250 million + who knows how much was spent for marketing and promotion ( yes, we should also consider that number too..Everyone talked about BVS and even included money spent for marketing, which means CW also should be considered for that discussion ).
In a nutshell; This is an Avengers movie pretending to be a Cap movie, expecting to perform like Avengers and not like a Cap movie. That's all.