I stumbled upon kalliope recently (https://github.com/kalliope-project/kalliope). I tried it a few weeks ago and was pleased with it in general but it still needed an online connection in order to parse your commands. According to the changelog they added the option for an offline STT recognition now.

Neither of those options is very scriptable either. They just kinda suck. None of them have any compatibility with actually used home automation ("computer ! lights !" is actually useful). You're right. We need an assistant that's just a piece of software. Paid for, working for me, not caring which messenger it has to use.

Yup. I'm not really going to be interested in this landscape until i can get a full NLP / Intent Recognition / Voice Transcripting package in my home, completely offline.

I'm not even paranoid about the NSA/etc either, i'm paranoid about a potential 3rd party listening in and knowing when to rob my home, or viewing my family through the IP camera, etcetc.

I want a smart home. I don't want an internet connected smart home. It's simply too dangerous.

Scriptability, security, privacy, latency. The list goes on.