The Penguins are an old team, but somewhat uniquely, some of their oldest players are their best (Sidney Crosby, Evgeni Malkin, Kris Letang, Erik Karlsson). Sure, you could say that those players aren’t at the level they were five or ten years ago, but Crosby is still among the league’s top players, Malkin’s 65 point season is more than befitting of a second line center and Pittsburgh has two right-handed defenders who can score 50+ points and play 25 minutes a night with positive territorial, possession and goal results.
But these players are all still old. As seen throughout history both near and far, it’s much more common to be a high-end NHL team when a club’s best players are in their 20’s, not at 35+ (as all the Penguin players are, save Karlsson who as the “youngster” of the core turns 34-years old next month).