It's funny, because the wisdom that was often taught ( but essentially never practiced ) was "Refactor as you go". The idea being that if you're working in an area, you should refactor and tidy it up and clean up "tech debt" while there. In practice, it was seldom done, and here we have LLMs actually doing it, and we're realising the drawbacks.
This is horrible practice, and very typical junior behavior that needs to be corrected against. Unless you wrote it, Chesterton's Fence applies; you need to think deeply for a long time about why that code exists as it does, and that's not part of your current task. Nothing worse than dealing with a 1000 line PR opened for a small UI fix because the code needed to be "cleaned up".