If you're programming for a plane's avionics, as an example, the quality assurance bar is much, much higher. To the point where any time-saving benefits of using an LLM are most likely dwarfed by the time it takes to review and test the code.
It's easy to say LLM is a game-changer when there are no lives at stake, and therefore the cost of any errors is extremely low, and little to no QA occurs prior to being pushed to production.