Speech to text is one thing. Actually understanding all the intricate details and variations of language is incredibly difficult. It’s good enough for some stuff, but I’ve yet to see a system a system that’s reliable enough for day to day use, especially in a car.
Scenarios like this happens way too often:
“Set alarm for fifteen minutes”
“Ok, setting alarm fifty minutes from now”
“No! FIFTEEN minutes”
“I’m sorry, I don’t understand what you mean”
“Remove old alarm and set it to fifteen minutes instead”