Interestingly, some of Apple’s devices do already serve a special purpose like this in their ecosystem. The HomePod, HomePod Mini, and Apple TV act as Home Hubs for your network, which proxy WAN Apple Home requests to your IoT devices. No other Apple devices can do this.

They also already practice a concept of computational offloading with the Apple Watch and iPhone; more complicated fitness calculations, like VO2Max, rely on watch-collected data, but evidence suggests they’re calculated on the phone (new VO2Max algorithms are implemented when you update iOS, not watchOS)

So yeah; I can imagine a future where Apple devices could offload substantial AI requests to other devices on your Apple account, to optimize for both power consumption (plugged in versus battery) and speed (if you have a more powerful Mac versus your iPhone). There’s good precedent in the Apple ecosystem for this. Then, of course, the highest tier of requests are processed in their private cloud.