Do you want an elite winger-esque center that is extremely speedy and puts up points (mainly secondary assists)?
Or do you want the elite Selke calibre big center that dominates both ends of the ice (most of his points are goals) and puts individual achievements secondary to team achievements?
That's how I see it.
I think the really funny thing here is that you tried to point out that most of his points are secondary assists, when even a cursory glance at the statistics would show you that most of his points this season have come from goals, then primary assists, then secondary assists.
It would have been possible for you to look less informed here, but it would have been pretty difficult.
McDavid is the better player. Matthews is on the better team. That's it. That's not a knock on Matthews, because he's a great player in his own right, but at this stage in his career he's not as good as McDavid is.