The talent is undeniable.
The question with players like these is whether they feel the need to dominate the ball (ala John Wall, Russell Westbrook) or can play within a ball movement system while using their slashing and play-making ability.
Generally speaking, point guards who dominate the ball don't lead championship teams. There's just something about the way defenses can respond in the playoffs.
It is possible to have a point guard be one of your best players on the team and win a championship, like Steph Curry, Tony Parker, and Jason Kidd.
This is one of the reasons why I like what Irving has done so much. He could have stepped in to the Celtic system and dominated the ball, putting up way bigger numbers than he does, but he wanted to learn a ball movement system. I think he has and continues to get better with it.