Dembele can be the best winger in the world.
This guy has everything. Pace, dribbling, technique, shot power, crossing/passing accuracy, both footedness...
If you created a touchline winger in a lab it would be him.
Sorry but there is no way Raphinia is better than this guy even if he does score some goals and is pretty good. Dembele is world-class and that's undisputable. Just make sure he's playing consistently without injury and he will develop into the best winger in the world.