The difference is, the total cost for a human to write/modify code files is much higher than for an LLM. A lot of time has been spent designing program language

The difference is, the total cost for a human to write/modify code files is much higher than for an LLM. A lot of time has been spent designing program languages so that human time is more optimized. LLMS dgaf if the code is structured cleanly or is a mess. So even if you end up with a mess of a codebase, as long as you define your test cases and they all pass, what is in the middle doesn't really matter.