Player development isn’t linear. Some guys prove to be world-beaters at the age of 20 whilst others start to figure it out closer to 30. On one end of the spectrum, you have phenoms like Felix Hernandez who just get it and dominate the sport as teenagers. But more commonly we find teams relying on late bloomers like Chris Flexen to help bolster the 26-man roster later in their careers.
Just look at how the Mariners got their wins in 2021. Ty France burst onto the scene cementing himself as one of the more reliable hitters in the American League.