As someone who uses machine translation on a daily basis, I've watched it go from being barely usable to as good as human translation for most tasks. It's really uncommon that I find issues with it any more. And even if there is one issue in 1000 words or whatever, you can just have a human proofread it instead of translating the whole thing, it will reduce your headcount my 90%. But I think for most things, no one calls translators any more, they just go to google translate. Translators now only do realtime voice translation, not documents which used to be most of their work.
These things creep up on you. They aren't good and you get comfortable that they don't work that well, and then over time they start working as well or better than humans and suddenly there's really no reason to employ someone for it.