You end up with a nice spec that you wouldn't have had otherwise? That has value even if you discard all the LLM-generated code.
I think experienced engineers are able to go straight from a vague requirement to an implementation without that intermediate step, and that power is easy to abuse. We build an implicit spec on our head, which gets translated to code on the fly, and then gets forgotten.
Not defending the LLM technology, but i do think this is one of the upside.