In reality, there is no use-case for hosting LLM model on a mobile device. What can it do there? Autocomplete short chat messages up to the whole sentence? Too heavy artillery for that.

Copilot? For what? What one would ask it, with these small keys on the mobile keyboards?

Writing essays? On mobile devices? I don't think so...

AI & LLMs are for devices that create content. Mobile devices are only content consumer devices. No need of AI there.