I use an LLM primarily for smaller, focused data analysis tasks so it's possible to move fast and still stay reasonably on top of things if I'm even a little bit careful. I think it would be really easy to trash a large code base in a hurry without some discipline and skill in using LLM. I'm finding that developing prompts, managing context, controlling pace, staying organized and being able to effectively review the LLM's work are required skills for LLM-assisted coding. Nobody teaches this stuff yet so you have to learn it the hard way.
Now that I have a taste, I wouldn't give it up. There's so much tedious stuff I just don't want to have to do myself that I can offload to the LLM. After more than 20 years doing this, I don't have the same level of patience anymore. There are also situations where I know conceptually what I want to accomplish but may not know exactly how to implement it and I love the LLM for that. I can definitely accomplish more in less time than I ever did before.