Cruise is dependable.
When you go watch a Cruise-movie these days you know what you're gonna get.
If you want to see a Sci-fi movie that you know has a great budget played by that same dependable character (that Cruise always plays), Cruise is your choice of actor.
Oblivion, Edge of Tomorrow, Jack Reacher, Mission Impossible etc same type of character.
Only time Cruise went out of his way to play "someone else" was in Tropic Thunder.
With Cruise, you KNOW what you're gonna get.
With Brad Pitt, you can get anything from Autumn Legends, Joe Black, Fight Club, Troy or whatnot.
He's made lots of bad movies but several good ones too.
Not as consistent as dependable Top Cruise.