Those are applications, not interfaces. No one controls those applications with their voices, they use buttons, either touch or mechanical.

Just because you don't doesn't mean other people aren't. It's pretty handy to be able to tell Google to turn off the hallway light from the bedroom, instead of having to get out of bed to do that.

They talk to other humans on those apps, not the computer. I've noticed less dictation over time in public but that's just anecdotal. I never use voice when a keyboard is available.