> even though I have faster models available I still go to Fable or GPT-5.6 90% of the time

What about all the things you don't currently use an LLM for?

If a specialized chip can run a model 100 times faster, you can suddenly use it for a lot of things at sub-second latency. You can write "make white transparent and add a red outline to x.png" instead of the corresponding imagemagick invocation and perceive little to no latency difference. You can hook it up to your browser and have it yank out all advertisements live, or tell it to highlight anything that might interest you, again, live. There's probably thousands of latent use cases nobody has thought of that would be enabled by a truly fast LLM, even a mediocre one.

I don't think an on-device model needs to change much; it's already quite general in its capabilities.