Being clueless has in my experience previously been a rate limiter. Without LLMs these people would simply be much less productive than those with a clue, and problems they don't understand would at best compel them to read and learn, and at worst to simply avoid going too far out of their depth. Either way, it would significantly slow them down compared to their more skilled and experienced peers. The resulting rate of output practically limited the burden of reviewing and maintaining it. Then, eventually skill and experience would hopefully just sort of happen to those that work for it, through exercise and exposure to problems and review feedback.