You can fit a Q5 Llama-3-8b or many other models on new iPhones.
Almost all Apple devices (including most Macs) have very low amounts of memory so Apple hadn’t really positioned themselves that well if their goal is running LLMs locally.
You need it to understand what you want to do within the limited scope of the phone.
Basically I want Apple's AI to do what Shortcuts is capable of today, but instead of a janky Scratch programming style, I want it to respond to speech.