Well no tactically it's because Higuain makes runs and turns defences so the opposition defence doesn't simply have to put up a wall and watch all the play in front of them. Higuain is a #9 so it's something different, not particularly better.
That too, but if we had better wingers/healthier wingers and a more functional/dynamic midfield, we'd be in a much better position. If we had that, we'd be able to stretch the play, pulling players out of position, thus creating more space for Dybala.