His skillset is absolutely ridiculous. His football IQ is outstanding, as is his passing, crossing, shooting, dribbling, running, pressing. He can do it all in a manner that is pretty much unrivalled.
Purely based on that he’s one of the best midfielders of all time. Also his performance levels during league seasons are extremely consistent, he’s far from a ”what if” player.
Then again, playing for City & Belgium and repeatedly failing to deliver something special on the decisive moments of the most prestigious cup competitions will hurt his legacy severely. It’s not like he has to do it all by himself, but without winning anything other than bunch of domestic titles with an oil club, he’s never gonna get the recognition he deserves.