If you want real-time speech recognition with less than 0.5s of delay between speaking the word and it being fully recognized, then one needs to implement a different architecture. And that one is much more difficult and expensive to train that this one (which was already expensive).
That said, I want a fully offline and privacy-respecting voice assistant myself.
So attempting to build the AI for real-time streamed live English speech recognition will be my next project. I plan to ship it as an OpenGL-accelerated binary with WebRTC server so that others can easily combine my recognition with their logic. But it probably won't be free since I'm looking at >$100k in compute costs to build it. In any case, here's the waiting list: https://madmimi.com/signups/f0da3b13840d40ce9e061cafea6280d5...