But when it comes to the final act I find myself unwilling to let an LLM write the actual code - I still do it myself.
Perhaps because my main project at the moment is a game I've been working on for four years, so the codebase is sizable, non-trivial, and all written by me. My strong sense even since coding LLMs showed up has been that continuing to write the code is important for keeping it coherent and manageable as a whole, including my mental model of it.
And also: for keeping myself happy working on it. The enjoyment would be gone if I leaned that far into LLMs.