Chat sucks and will be replaced in almost all cases, I suspect. Speaking is much easier for many tasks, traditional UIs for others. Mediating everything through a keyboard is clunky and slow.
I very much doubt that speaking is slower than typing, given that basically only stenographers can transcribe things in real time, and that's by using special technique.
Talking is still faster, and I can do it while my hands and eyes are occupied, so I definitely don't see typing ever being the preferred interface. You'd never type to interact with an assistant while driving.