Matthews isn't McDavid, not even remotely close. McDavid is by FAR the greatest player of his generation. Maroon 30 goals, Hyman having career years, even Draisaitls numbers with McDavid and on the PP with McDavid, vs away from McDavid have a significant difference.
McDavid will inflate any players numbers, it's not exclusive to Drai. If somehow Matthews was on his wing, I legitimately believe he scores 80+ goals, McDavid is THAT dominant.
Draisaitl is more in the range of players like Kyle Connor, Mikko Rantanen, Mitch Marner. If he ever plays on another team, you will see it for yourself. Numbers have people fooled.