LLMs change not a whit, and there's no one to take responsibility for the failure (and thus no way to fix it).
As the new variation on the old theme has it, "A computer can never be held accountable, and so very many people are trying to get them make management decisions."
But they do learn and improve.
The models don't (yet).
It might be that the models have been improving in this sense faster than a human child improves.
LLM output is nondeterministic and humans take responsibility for the failure the same way they take responsibility of a photocopy is too dark.
You mean, they notice it's too dark right after making it, change the settings, do it again, and give you the good copy?
Because yes, that's my experience of humans.