Simply put, he has an NBA body and reads the floor. He has a sense of confidence with the basketball and just plays poised all the time. It helps he knows exactly where to be and what to anticipate on both ends of the floor. This kind of reading ability, a lot of NBA players don’t reach.
What makes him appealing? He’s just mobile enough to be switchable, but reads the game so well, he’ll likely be neutral defensively as a big wing and possible back up 5 as a rookie, which is an absolutely big deal.