The finest perk of winning a major might just be the way it can impact literally the rest of an entire career. Even a single major victory guarantees that no matter what else happens in your career, you'll be playing that major for years, even decades into the future. But then, the opposite corollary is true: If you can't manage to secure that major win, it will haunt you for the rest of your days.
Tiger Woods hasn't won the British Open since 2006. But he's still won it three times, which is three times more than you, me or Colin Montgomerie.