But we are not talking about large volumes of code here; we are talking about; LLM generates something, you check it and close read it to spot logic bugs and either fix yourself, ask the LLM or approve. It is very puzzling to me how this is more work/taxing than writing it yourself unless for very specific examples;

Examples from every day reality in my company; writing 1000s of lines of react frontend code is all LLM (in very little time) and reviews catch all the issues while the database implementation we are working on we spend sometimes one hour on a few lines and the LLM suggest things but they never help. Reviewing such a little bit of code has no use as it's the result of testing a LOT of scenarios to get the most performance out in the real world (across different environments/settings). However, almost everyone in the world is working on (similar issues like) the former, not the latter, so...