Do you ever find yourself asking what happened to Josh Hartnett? I get that different artists have their dedicated fan bases who they manage to find success with, and that they become known for a certain "thing" that they do, a specialty if you will.
These are the actors who are capable of standing the test of time because they're constantly sharpening that one "thing" they're working on. It doesn't matter how old they get, it doesn't matter what movies they've appeared in, you can always count on them for bringing that to the table.
Whether it's Bill Murray, Christopher Walken, Helena Bonham Carter, Gary Oldman, Lily Tomlin, Dustin Hoffman — I could go on and on, these peeps will always, always, always bring whatever they're working with to the set, and you can count on them being 100 percent themselves in whatever role they're asked to play. It's beautiful, it's consistent, and it's reliable.
These "career-ists" can't be mistaken for anyone else, and, depending on what point in their career they're at, they may be featured in some blockbuster films, or get the spotlight as a lead in whatever story's being told. Some of the movies they're in are better than others, but they work and probably always will work — as long as they keep sharpening their craft. But staying a "top blockbuster star" isn't something that's usually sustainable and/or attainable for most talent. Just ask Johnny Depp.