I believe it's because it's at least a magnitude more expensive to run an LLM instead of a basic voice assistant ML model. Especially when considering anyone who has purchased a Google Nest Mini can use it, for free, forever.
Fixed responses for common queries is what we have now.
Not to mention that LLMs tend to be very wordy right now. I’d hate to way 20 seconds to hear my phone say “As a voice assistant I’m not aware of the exact menu of the Thai restaurant on 2nd, but I have opened a google search for it and found the following results.
…”
Is that a contractual obligation? otherwise what stops the Mini from going the way of a Jamboard?