Dembele was a good, possibly great player who might have become world-class. In one-on-one situations then he was rarely bested, when he had the ball the opposition then the opposition doubled-up or even tripled-up on him thus leaving other Spurs players open. In that sense he opened up the opposition. But to be truly world-class then I'd say that he would have needed to be better on the final pass or the shooting. The best way to deal with him might have been to let him have the ball - he seldom managed to do something dangerous with the ball so let him dribble around and if/when he gets to close to danger areas then crowd him out and his only way out was to pass backwards. Defensively then DMs like Kante were/are better, offensively then Dembele was good up until the (all important) final third. Maybe he could have been world-class, as is then I'd say that he was good/great and did great for Spurs.