There is a pretty big disparity in what they've done in the last 2 years. Matthews is 2nd in goals since he came into the league. I can't even imagine how crazy Laine fans (and I mean Laine Fans first and somewhere after Jets, if at all) would be if he was attached to Hyman for his first 2 years in the league, considering how often they blame his linemates for not reaching some of the heights they predicted for him, and its not like he has gotten significantly less time than Matthews or Pastrnak in that 4 year time frame.
The argument you responded to didn't say Laine was one of the best young goalscorers in the league. It said he was the best. Which sort of brings Matthews into the discussion, since he's been the better goal scorer, is from the same draft class, and seems way less relient on linemates to create goal-scoring opportunities for him.