guys like Kucherov and McDavid and Matthews are able to account for so many goals/assists when they're on the ice for a minute at a time? these guys are apparently doing the vast majority of goal creation but only playing 30% of the game. Is there huge talent disparity from the dudes playing on the first shift vs the fourth? Why do things really only seem to happen when the best players are on the ice?

If this is a really stupid question, feel free to make fun of me. I'm just excited to learn more about the game.