Having used Claude Code extensively for the last few months, I still haven't reached this "until it isn't" point. Review the code that comes out. It goes a long way.
Sure, but if I do 5 reviews for a task - in 99% of cases it is net negative as it is faster to DIY it at that point. Harder for sure, but faster.
Coding is easy, it works or doesn't.
With only "it works" you end up like this (iconic HN comment on Oracle codebase): https://news.ycombinator.com/item?id=18442637