I have been using voice input for a long time. It's really good for typing long text. But with one UI 6 , voice input button from the toolbar is gone. I use swipe gestures and done keep the bottom bar for max screen area. But with new voice input method, I am forced to keep the navigation bar for showing keyboard/voice input button. It's really a weired change. Since camera input is in the toolbar, why not keep voice input at the same place.
Ps: There was a tutorial to long press spacebar button to start voice input. That also requires the voice input botton in navigation bar.