Voice Assistants for desktop PCs were available way before the existence of the very thought of having one on a mobile device. Unfortunately a very small percentage of desktop PC users utilize them even though such software programs are more complex and could provide better results.
The reason behind this it’s because desktop PC experience was not originally designed to be voice assisted. Apple has already integrated voice dictation on OS X but up until now there’s no rumor of having Siri brought to OS X as well. Google is now about to upstage Apple’s Siri again by competing on Desktop PCs against companies such as Nuance (for more read -> http://voice-software.org/speech-to-text/dragon-naturally-speaking.html).
Google’s popular Chrome browser might soon have already existing Google Now voice assistant service built in. Since Google already has over 40 percent of the browser market share this is worrying news for Apple. Chrome is popular on the Mac as well and having Google Now there before Siri might ruin Siri’s chances of success on the OS X.