I certainly can't speak for anybody else, but I've played a number of superhero games over the years. My main takeaway from them is that they don't feel - to me, at least - like long campaign stuff. They've worked wonderfully for short adventures of a few sessions or so, but for some reason they've never gone on longer than that.
That could just be the games I've played, of course.
That could just be the games I've played, of course.