In the future a keyboard will be a vestigial organ. Monitors will not be monitors. You will either wear a head set or stare at a wall or look at your Linux-powered smartphone.
As you already know, I disagree with this assessment. Interestingly that very similar statements can be found going back to the 80's. I seem to remember some people expressing similar viewpoints in episodes of "The Computer Chronicles" for example dating back to the 80's and 90's.
However while the technologies proposed to replace our standard input devices- speech to text and text to speech for example- have become valuable- you use dictation software, for example, and people who are blind use text to speech to "see" their screens- I don't see them being used to replace the keyboard for a typical user anytime soon, just a value-add for certain users individual needs.
I mean, let's think critically here- these sorts of devices and features all have a certain inexact quality- dictation software misunderstands you, and text to speech mispronounces or misreads text or reads text incorrectly; features like motion control- intended to replace the typical gaming interface of a Game Controller- has it's own issues as well. It seems that the more "intuitive" an interface is supposed to be, the more can go wrong.
What makes keyboards so everlasting (and game controllers for many games I suppose) is that they enforce something that people generally expect when using computers- that "To err is human". With other interfaces intended to be more "intuitive", gestures can be misinterpreted, speech misunderstood or misinterpreted, text mispronounced, etc. But it is humans which make typos when using keyboards (or game controllers).
That isn't to say it is impossible, I just don't see it as very likely; I mean, as it is, we haven't even really gotten toasters down. They seem to either deliver slightly warm bread, or pre-fired charcoal.
