Well, it's always a matter of opinion, and imo Modric deserved it, and even if it's debatable, it's hardly a scandal or something. He's hands down the best midfielder in the world and his contribution can't be measured as easy as Ronaldo's or Salah's (goals/assists).
I might be slightly biased about this, but it's been about time they give credit to a midfielder instead of handing the award to a striker again. That, and that it isn't really undeserved. He's been a consistent beast of a CM for years now.