Well, the results haven't been ideal for pitching. But let's also be real; where did Justin Steele, Cade Horton and Daniel Palecia come from? It hasn't been entirely barren, either. That number needs to be more, especially today, but we too often act like it's zero. And there is more coming. There are some interesting arms in the system, and I'd guess more than one will pan out in some fashion to add to the list.
Plus, on the flip side, where did Ian Happ, PCA, Javy Baez, Willson Contreras, Michael Busch (acquired for drafted prospects), and Nico Hoerner come from? Among others (such as Matt Shaw, Pedro Ramirez, Moises Ballesteros...)
The pitching can certainly be better. But when we complain about the pitching development it also ignores how well the Cubs have done with position players. They have drafted and developed there phenomenally. So there are two sides of the coin.
If you want the Cubs to be experts at both simultaneously, then I think that's an unfair ask. I would like it a little more balanced, but because the Cubs have spent their prospect capital on hitters, they have panned out well there. Very few teams have developed as many players as the Cubs have there, as well.
It's probably best to look at everything holistically. Because more lottery tickets into pitching almost assuredly means their position player output is much lower, too. With no guarantee those pitching lottery tickets panned out.