That one's been a head-scratcher for me. There are three IFAs who are either in the majors or are majors-adjacent (Mo, Pedro, Rojas), but those guys were 2021/2022 signings, and the classes after them have been decidedly not good. I remember in the last few years there were stories about the Cubs restructuring their scouting departments, and wonder if that has anything to do with it, but it does seem like their 2023 class (notables: Derniche Valdez, Ludwing Espinoza, Angel Cepeda, Jostin Florentino, Alexey Lumpuy, Eriandys Ramon) and 2024 class (notables: Fernando Cruz, Robin Ortiz, Yander Maria, Edgardo de Leon) haven't panned out yet, although there's still time.
It's not to say they screwed things up from jump because guys like Cruz, Valdez, and Espinoza were highly regarded when they signed, but it's hard to tell if these results were because of flawed scouting, flawed coaching, flawed player development, bad luck, or something else.