If you try to replace your whole job with an LLM, yes you will have problem. I work in IT, I use ChatGPT daily to spit out scripts, ask it to come up with function names, convert code from a technology to another, ask it to do minor refactoring that I don't know how to do.

I can immediately validate the output, learn from it, and even work with techs I'm not familiar with.

So you use it for generation where validation is easy. If validation were harder, the calculus would change.

I also get a lot of mileage out of it, but it is important to recognize its shortcomings.

There are plenty of use cases where validation is easy.

of course, I don't try to replace my whole job out of it. ChatGPT is 'good' at doing statistical analysis with python on a given dataset, that can help in the harder task you quoted "distinguishing between ideas that are correct, and ideas that are plausible-sounding but wrong". The job itself cannot be easily verified, but you can use LLM on a subset of theses tasks.