LLMs have uses, some of them are even quite intriguing. But they have to be properly trained. You can't just throw the whole internet at a baby with very little other training and expect them to not be corrupted by random wrong information. Same goes for LLMs though on a much larger scale. Also, they are often configured to give an answer even when the confidence in it being correct is relatively low. Something an expert would never do, they'd consult only specialized information, not just review the top search results on Google. This is one reason why they "hallucinate". Commercially trained models just aren't all that useful as a source of information or to correctly complete tasks. And additionally there are extreme ethical concerns about how it gets the information it's trained on including using hacking botnets to impersonate a human among other things. A person who's an expert has to review everything in excruciating detail and so most of the time it's just more cost effective to just consult an expert in the first place. It's like going to a proverbial used car car salesman and asking how cars work. Sure they might have picked up a fair amount of information from being around mechanics, but some of it is wrong and what they don't know they'll just make something up that sounds mostly plausible.