The bigger the sample size the less those things are meaningful other than the real player impact. Those other things become more and more just noise, and the bigger the sample size the more meaning the plus minus has. And anyway even inside the games the only meaningful stat for the game results is the goals and the goal difference. They decide the winner of the game. It doesn’t matter in the end how those results were achieved, as the better team is ALWAYS the team that scores more goals in a game. A hockey game is after all a competition of which team scores more goals. How they score the goals is irrelevant as long as they score more of them than the opponent.
The more you have skill, the likelier you are to score - especially in the long run. Thus, the bigger the sample size of goals and goal difference, the more it tells of the real quality of the player. More than any other stat.