He's not “the Greatest Living Actor”, however Brad Pitt's appeal as an actor should be obvious.
Versatility is not his forte, but he may well look like the smartest actor.
Brad Pitt’s back-catalogue is rich: Thelma & Louise, True Romance, Seven, Fight Club, Ocean’s Eleven and The Assassination of Jesse James by the Coward Robert Ford are all landmark films. In just the last decade, Pitt has starred in another glut of great films (Inglourious Basterds, Moneyball, The Tree of Life, 12 Years A Slave, The Big Short, Once Upon a Time in Hollywood)
He continues to make such films – for the most part, dramas aimed at adults.
World War Z excepted, Pitt doesn’t do blockbusters.
Tom Cruise, who was considered by Tarantino for Pitt's role in Once Upon a Time in Hollywood, is the only other actor of the age whose run of success is comparable to Pitt's own –though he became a glorified stuntman in mediocre action movies
Pitt makes the kind of films that we'll be talking about long after Knight and Day or the Mummy reboot have been forgotten.
In 28 years Brad Pitt's star has never truly waned