For one potentially compelling example that happily (sadly?) isn’t using LLMs: the SimulaVR people are developing their own Linux fork of some kind, claiming it’s necessary for comfortable VR use for office work. And I sorta believe them!
Natural language interfaces belong at the periphery, as the interface between the human and the machine. Other than that, I want my computers dumb as rocks, really fast, any totally predictable - which is basically the opposite of what you get from LLM's.