It's not one guy. When was the last time we had a 3 year window with pitchers coming up like Bello, Houck, Whitlock, Crawford and Wink?
These aren't great names, but look at the names before them: DHern, Shawaryn, Owens, Johnson, Ranaudo, TBall, Webster, de la Rosa and yes, Kopech and Beeks,
How is that not viewed as improvement, even if it's all blind luck.