I guess it depends on what you mean by voice assistant.

But Android has been 100% accurate for simple commands for over a decade for me. Things like:

- "weather." tells me forecast of where I am.

- "alarm at 8am" and "alarm in 30 minutes" works as expected.

- calendar commands also work

My favourite is "go home" which opens Google map with a route to home.

These things just work. I don't recall last time I had to repeat myself.