Probably a lot of good actors get mostly secondary roles. The better they are the less you notice them.
They also tend to be extremely versatile and avoid type-casting. I'm thinking a good example would be Tom Wilkinson who in the last decade or so has played Cornwallis, Benjamin Franklin, Carmine Falcone in two Batman movies, Friedrich Fromm and a Roman Catholic Exorcist...among many other roles. Excellent and hugely underrated actor.