Absolutely nothing, because they all give fucking useless results. Hallucinates, is confidently wrong, and isn't even grammatically competent (depending on the model). Not even good for a draft, because I'd have to completely rewrite it anyway.

LLMs are only as good as the guys training it (who are mostly morons), and the raw data they train on (which is mostly unaudited random shit).

And that's just regular language. Coding? Hah!

Me: Generate some code to [do a thing].
LLM: [Gives me code]
Me: [Some part] didnt work.
LLM: Try [this] instead.
Me: That didn't work either.
LLM: Try [the first thing] again.
Me: ... that still doesn't work...
LLM: Oh, sorry. Try [the second thing again].
Me: ...

Loop continues forever.

One time I found out about a built-in function that I didn't know about (in LLM generated code that didn't work), and read the manual for it, and rewrote the code from scratch to get it working. Literally the only useful thing it ever gave me was a single word (that it probably found on Superuser or StackExchange in the first place).