Why are you comparing its error rate for repetitive tasks with most people? For such mechanical tasks we already have fully deterministic algorithms to do it, and the error rate of these traditional algorithms is zero. You aren't usually asking a junior assistant to manually do such conversion, so it doesn't make sense to compare its error rate with humans.

Normalizing this kind of computer errors when there should be none makes the world a worse place, bit by bit. The kind of productivity increase you get from here does not seem worthwhile.