Machine translations are often brought up as a gotcha whenever I criticize LLMs. It's worth pointing out two things: Machine translations existed decades before LLMs, and yes, machine translations are useful. However: I would never in my life read a machine translated book. Understanding what a social media post is talking about in rough terms? Sure. Literature? Absolutely not. Hell, have you ever seen machine translated subtitles? It's absolute garbage.
I have the impression that primarily anglophone people don't read as much translated literature, because so much good literature already exists in their language, so this issue may not be as familiar within that demographic. As someone who did not grow up anglophone, I can tell you there is a world of difference between a good and a bad translation even when done by humans. Machine translations are not even on the scale.
@Gargron I'm willing to guess that machine translation of prose may serve two uses: firstly, as an assist for human translators (by preparing a very rough first cut, which they then have to refine), and secondly, as an assist for human editors in figuring out which foreign-language-works to pay a human translator (with or without AI assistance) to work on (translation costs money: knowing where to spend it is important). But those are assistive roles, not human-replacing ones.

@cstross @Gargron
Machine translations are more of a hindrance than a help, for translators. If you don't know both languages well, having an automated dictionary lookup could possibly be useful - but if you're a translator, and especially a translator of fiction, having a nuanceless draft will only take more time to figure out. And it will be irritating time, because reading mistranslations is a pain. Editing one's own drafts is hard enough!

As to B: Editors rely on readers, reviews /...

@cstross @Gargron
and the sort of awards that give a book the sheen of "worth reading".

My cred: I've translated more books than I can carry. Both fiction and technical.
My current position is that use of AI in translation is malpractice.

@Shunra @cstross @Gargron
My go-to example is the Esperanto translation of Alice Through The Looking Glass published by Evertype, which has 5 different translations of "Jabberwocky", each of which is absolutely "correct" and each of which is totally different from each other. Even the names of the poem differ.
In each case one can see the decisions the translator made balancing meter, rhyme, meaning, implications & nuance of the text, based on what it meant to them; how can a computer do that?
@HighlandLawyer @Shunra @cstross @Gargron i’ve always found the wealth of translations of ‘the little prince’ to be fascinating, and the way folks can trace back certain choices, showing that x translation was actually based off of y translation instead of the original french, &c.