I think it has less to do with everyone switching to Apple silicon and more to do with the clarification of viable business models: you either become an IP company and outsource production (AMD) or you go completely vertical and design and produce custom-designed SoCs to be used exclusively in your consumer products (Apple). The Intel model of designing and producing all-purpose commodity CPUs seems to have hit a wall due to both lack of demand and unanticipated manufacturing problems.