Here's an opinion from someone who can see and has been in the IT world for decades now: Voice control of everything is not now and never will be "the next big thing" nor the primary interface to computers for the vast majority of users and the vast majority of tasks.
Others have already pointed out, and very well, why this is true.
One of my previous clients required the use of Dragon Naturally Speaking to do everything with his computer. It has come leaps and bounds from where it started, including speech recognition with very minimal training for an individual with a markedly atypical speech pattern, with very minimal training of the software. Even with that being the case, controlling a computer and all its functions by voice, even for a very skilled user, is far, far, far slower than accessing it via a keyboard or other "finger driven" interface. This is particularly so with regard to text-intensive applications, where one is endlessly pausing, thinking, jumping back a word or two and correcting or inserting something, etc.
Most of what I do on a computer every day is not nearly as amenable to efficient and easy control by voice as it is via the conventional keyboard and mouse.
Reports of the death of technologies that are the direct descendants of things that have been in use for over 100 years now are being greatly exaggerated. The manual typewriter, electric typewriter, dedicated word processor, and word processor software - as well as things like e-mail - haven't hung around using a keyboard because voice recognition is not plenty mature enough to handle them. Anyone who uses a smartphone and texts via voice knows just how eerily accurate voice recognition is "out of the box" for myriad voices and accents these days. They also know that as soon as they get beyond a sentence or two that using dictation usually begins to feel really, really messy compared to the "think and type, think and type, think and type" cycle does for anyone who has been trained in how to type efficiently (or even not so efficiently).
Brian - Windows 10 Home, 64-Bit, Version 1803, Build 17134
Explanations exist; they have existed for all time; there is always a well-known solution to every human problem — neat, plausible, and wrong.
~ H.L. Mencken, AKA The Sage of Baltimore