It should not have been. Marvel Studios wanted to adapt Civil War and used Steve's movie to do it. It was going to introduce Black Panther. And then Disney got the Spider-Man license and made room to introduce him too. But it did all take away from being a Captain America movie. And I consider the worst in the character's trilogy. But it was pretty much Avengers 2.5. The Marvels is not adapting any specific storyline. It was changed because they fear failure. The first one did decently because the MCU built up good will from the first bunch of films, but the recent installments have been faltering and that good will is wearing off.