Case in point, Derek Stepan--the player you think has "plateaued"--is only 10 months older than Kreider. Here are some hard cold facts: He has played six seasons, to Kreider's four. Stepan has four seasons with higher numbers than Kreider's career high--while also being far better on the defensive side of the game. The two seasons where Stepan was below Kreider's career year were his rookie year, where a 20 year old Stepan was exactly one point off of Kreider's high mark, and the lockout year, where Stepan put up 44 points in 48 games. In other words, basically every single one of Stepan's seasons has seen him be at worst equal to, and more often than not BETTER than Kreider's career highs.
Stepan IS the significantly better player, and I don't really see that changing. You need to stop acting like Kreider is on par with MacKinnon and that Stepan is hot garbage. It's not based on anything factual, and you are literally the only person who believes it.