It might be an issue with processing power. The new NPU might fit nicely in this case.

Apple has had stripped-down versions of this before on both iOS and macOS via Voice Control.

There's a big difference between recognizing "open the photos app, computer" and "what times is the avenger's showing today, Siri?"

How do you plan to get the Avengers showtimes without connecting to the internet?

You misunderstand what the internet connection is for. Right now most machine learning models run on server farms and your voice snppet is sent to the server, where the model processes it. They then send the interpretation back

"Local model" means the voice snippet is processed on your device. Never beamed off to a server farm.

The interpretation might be:

  Action: internetSearch
  QueryString: movie times for "Avengers" [near me || {userPreferences.movieTheater}]
  UseLocation: true

Which then kicks off whatever process Siri has for handling internet search actions