McDavid is 4th all-time in pts/g in the playoffs... He is 2nd only to his teammate Draisatl in the current era and that will change once more games are played.
If you don't think pts/g is a good measurement for the best players (forwards at least), then please explain away the fact that Gretzky leads all-time pts/g for both the regular season and playoffs.
McDavid has actually elevated his game unlike some other superstars I could mention (check your avatar), his pts/g is higher in the playoffs than in the regular season.