Just rewatched this for some reason. It was actually quite good for an action flick, and I think I understand why Marvel is so consistently beating DC in terms of popularity.
The answer is pretty simple. Disney. The pretext was that Marvel was taking a risk by letting Disney buy its studio. Ditto for Star Wars. But Disney has the best track record in history when it comes to popular franchises. Now Marvel is a Star Wars-sized cultural phenomenon. Bigger even. And forged in a much smaller amount of time.
Buuuut... I don't think any of these films are gonna last, or be talked about 10 years later like the (sorry) Nolan films. They rely too heavily on CGI. Some of the costumes are 100% CGI, and they're going to look dated as hell in five years.
Captain America is the best part. And out-of-costume RDJ. But watch: in five years Black Panther and Spider-Man are going to look like the first Toy Story.