That's fundamentally the real issue. LLMs are far from even animal level "cognition" in their ability to solve novel problems. A lot of people seem to vastly underestimate the number of novel problems they solve on a regular basis.
In practice, what we're seeing now is something akin to the first wave of "ai hype" that led VCs into a spending frenzy years ago. Some of it did materialize. Most of it didn't.
LLMs and their related bretheren are pretty cool. They're very useful for solving routine problems. There's a lot of "routine" work out there in the world and it will probably replace some of those jobs.
But just like CNNs led to a frenzy of innovation in image recognition and LSTMs pushed NLP-related use cases forward this too will hit a wall.
If I were a betting man I think the main industries LLMs will disrupt are:
1. Search. ChatGPT is decent at summarizing stuff which will make searching more natural. 2. QA/Testing. A lot of this work is pretty repetitive and manual and LLM assistants can generate skeleton code for tests, etc. pretty well. 3. "basic" programming jobs that use "frameworks" to slap together simple apps/websites. A lot of this is repetitive gluing of stackoverflow code already so ChatGPT will make these folks considerably more productive. I'm not sure that these jobs will even disappear either.
I'm surprisingly less bullish on ChatGPT replacing marketing folks. It may be used to generate copy but the risks of putting out brand-damaging copy or a marketing campaign that doesn't make sense are too high.