>I cannot imagine that machines will ever replace any work where there is any meaningful threshold for "correct".

For most of human history calculations were performed by humans. Entire banking systems were 100% dependent on humans, with some helpful tools, performing accurate calculations. The idea of not performing that work with machines is laughable now. Machines have replaced humans, especially when correctness matters.

Humans are also remarkably bad at being correct and most jobs have a very low impact. I think your perspective is skewed towards the job you are doing, which is in no way representative of most office work, which is mostly tedious, low impact and low stakes.