The 10x engineer is really good at deducing the next most important thing to do is and doing it quickly. This involves quickly moving past 100's of design decisions in a week to deliver something quickly. It requires you to think partly like a product manager and partly like a senior engineer but that's the game and LLM's are zero help there.
Most engineering productivity is probably locked up in this. So yes, LLM's probably help a lot, just not in the way that would show on some Jira board?
*One could claim that doing this slow work gives the brain a break to then be good at strategizing the higher order more important work. Not sure.