One thing people often don't realize or ignore: these LLMs are trained on the internet, the entire internet.
There's a shit-ton of bad and inefficient code on the internet. Lots of it. And it was used to train these LLMs as much as the good code.
In other words, the LLMs are great if you're OK with mediocrity at best. Mediocrity is occasionally good enough, but it can spell death for a company when key parts of it are mediocre.
I'm afraid a lot of the executives who fantasize about replacing humans with AI are going to have to learn this the hard way.