They don't neccesarily do, but you can get them pretty far, one of the most interesting parts of LLM's (I guess chat based, haven't tried copilot style ones well enough) is that smallish rewrites are really low cost

Don't like the way it did something convoluted or didn't do early returns? say it, it will do it, chain as many requests as you need, it won't get fed up with you, and if you see it losing detail because memory, use those requests for a significantly more polished prompt on a new chat for a cleaner starting point

Don't just accept what it gives you either