Great players, who can really put up points... but now do their performances beyond game 4. That's where the problem is, they completely disappear when it counts. Marner for example is a -6, with two points in six game sevens in his career. I'm not trying to pick on him, but I know that stat without looking it up.
Nylander had a great playoffs, except he had no points after game three against Florida. Marner had one assist after game three. Matthews had one goal, no assists after game three. Tavares had no points after game three.
Our most impactful player, after game three... was MAX DOMI... with three points... now congrats Max, but you just don't win this way.
Of course, a couple of games isn't a statistically significant event, but this is a repeated pattern now for nine years. Great regular season players, and good playoff performers early in a series, and then a disappearing act when it counts.