[Arubis]

Absent regulation or other incentives to nudge the market otherwise, the overwhelming majority of software is and will be written to use existing input methods--i.e. adding a new input method isn't the core competency of a team creating the world's best todo list app.

With that precondition, any voice-to-control layer on the desktop is in the tough situation of translating between voice input and a piece of software that was designed without voice input in mind.

Google and Siri, etc., aren't as beholden to the desktop/browser interface paradigm, so they don't have to perform this interface translation.