I don’t know, mileage varies but to me the Marvel films are so glossy and shallow that when they attempt realism it falls really flat.
I’m not opposed to an introspective, depressed Cap at all but I think you have to overhaul your whole approach to the movies and bring in better directors, better screenwriters, to start with.
EDIT: And I’m not saying Marvel films are shit, if you look in the other thread I ranked two of them very highly this year. I think they’ve made their bed with a certain style of colorful, quippy movie and if you’re doing this kind of Cap you need more of the Nolan touch.