None of what you describe is free.

After the LLM helps untangle the mess, if you leave the mess in place, you will have to ask the LLM untangle it for you every time you need to make a change.

Better to work with the LLM to untangle the technical debt then and there and commit the changes, so neither you nor the LLM have to work so hard in the future.

I’ve even seen anecdotal evidence that code that’s easier for humans to work with is easier for LLMs to work with as well.