Voice is simply natural to humans. Downloading an app to learn about the departure of the next bus is not.
I used voice bots to let my 5-year-old play role-playing games (e.g., checking into a hotel) or let my parents (60+) call a fake car dealership.
It's amazing to observe. They behave as if they're talking to a human, especially when doing it via a phone. That is exactly the UX a computer system should have—simply a phone number and voice.
As soon as people have to learn something new (a new webpage, a new app, etc.), something is wrong.