> but that makes it easier than ever to inflate codebases to millions of lines of unnecessary complexity that are impossible to work with and maintain.

Impossible for you, me, and other humans maybe. But not hard to understand for LLMs

> I want to see an LLM reduce a complex multi-million line codebase to 1/10th of its size or less without breaking functionality. That would be impressive!

They can and do, if you ask them to.

If you have tests to validate functionality, it can easily reduce and refactory.

But, why are we caring about LOC again?