A lot of the truly-good actors get called character actors and are considered less important than less-versatile leads. And of course sometimes (often, perhaps) leads are good, versatile actors but every director keeps demanding the same, proven-bankable performance out of them. You see this with someone like Adam Sandler, who plays the same couple easy-to-play characters in most of his movies that make him serious money, but can absolutely act when he needs to (which is mostly in movies that don't make him serious money).

IMO Brad Pitt is an example of a "leading man" who's actually at his best in character-actor type roles. He never quite developed that reliable-draw narrow tyepcasting that defines a lot of leads (Reynolds and Pratt are prime examples—you cast them in a big-budget movie for a specific reason, like, there's little question what sort of character they're gonna play) and seems more at ease as a rather offbeat lead or as a supporting character.