I wish somebody made a text-based assistant that has similar functionality. As a non-native English speaker I don't think voice assistants will ever become accurate enough to be usable by me.
I use voice2json on my homebrew RPi voice rig, and it has a plain-text input mode [0]. With a little Node-RED + MQTT + shell magic, it's pretty neat/convenient to type into the terminal: `house "turn on lamp"`. :)
Dexter has a couple of different input systems: PocketSphinx and DeepSpeech.
PocketSphinx seems to have better language coverage but lower accuracy than DeepSpeech, which only has English and Mandarin Chinese.
DeepSpeech was not great about 2 years ago when I first started Dexter and, being a Brit, I had to fake an (awful) American accent to make it work. It's come on well in that time though; I can use my own voice now, which is a relief to those near by. No clue how good its Mandarin recognition is however.
Other folks in surrounding threads have flagged Kaldi which I'll try to take a look at as well (though it also looks to be only English and Mandarin too).
[0] https://voice2json.org/commands.html#recognize-intent