precisely this. once someone figures out how to get something like GPT integrated with actual products like smart home devices and the same access levels as siri/google assistant, it will be the true voice assistant experience everyone has wanted.
Imagine if iOS had something like apple script and all apps exposed and documented endpoints. LLMs would be able to trivially solve problems that the best voice assistants today cannot handle.
Then again none of the current assistants can handle all that much. "Send Alex P a meeting invite tomorrow for a playdate at the Zoo, he's from out of town so include the Zoo's full address in the invite".
"Find the next mutual free slot on the team's calendar and send out an invite for a zoom meeting at that time".
These are all things that voice assistants should have been doing a decade ago, but I presume they'd have required too much one off investment.
Give an LLM proper API access and train it on some example code, and these problems are easy for it to solve. Heck I bet if you do enough specialized training you could get one of the tiny simple LLMs to do it.