I wrote the README from the perspective of being understandable by the lay person, and I think I left out some vital clues about this being a software building block for making your own ESP32 projects more intelligent. I pushed a README update to make it 0.1% more clear.
As for what to talk to.. or the ultimate purpose lol.. you could do simple device control scenarios ("lights off"), do hands-free sensor readings ("temperature at 95 degrees"), change wifi settings via voice ("switch access points"), etc.
I use it to control an agent-powered diverse device sensor network in my home and my truck. Much of the capability needs Internet access, but having on-device speech to text and text to speech means I can still do some stuff when I didn't bring the Starlink with me. On-device STT opens up a lot of low bandwidth (lora) opportunities too.