Add to that the fact that we can't blindly trust LLM output just yet, so we need a mearbag to review it.
LLM will always be more expensive than human +LLM, until we're at a stage where we can remove the human from the loop
The costs do exist somewhere though, and must be paid by someone. There's no free lunch, and the human lunch is very likely far more costly than the LLM lunch.
> Add to that the fact that we can't blindly trust LLM output just yet
Can't blindly trust human output either. That's why there are various tiers in roles, from junior-equivalent to senior-equivalent, and the actual user of the product is always the final arbiter. There's ultimately nothing different, except that the LLM iterates on issue resolution in seconds to minutes, whereas the human equivalent takes hours to days.