The problem is that the G4 problems break the narrative about the PPC->Intel transition resembling an Intel->ARM transition. The reason the G4 stagnated was because Motorola was heavily focused on embedded processors and didn't prioritize the Mac. There's a similar risk with moving the Mac to A-series, Apple-developed ARM processors because Apple themselves have been prioritizing mobile devices over the Mac in recent years, leaving a significant risk that desktop-class and even laptop-class processors from Intel and AMD will once again leave them behind in performance.