With all these Speech API's from the likes of Google, Microsoft that operate in similar ways (put data in, get data on what it thinks you said out) I wonder wha

With all these Speech API's from the likes of Google, Microsoft that operate in similar ways (put data in, get data on what it thinks you said out) I wonder what the difficulty is in interacting them via common interface. That way the user could pick their poison from the choice of speech APIs, or even use a local solution. Curious if there is examples of something like this already around?