I've had to translate a whole bunch of letters from English to Finnish for my grandparents, and doing it using a translator saves a ton of time as I don't have to actually produce the text, I can just read both sides afterwards and as long as every sentence matches in meaning, I can move to the next one.

But I wouldn't trust it to actually be correct for the entire thing, because it never is, and if someone who doesn't understand one of the languages would do it they would never spot the mistakes either.

How good is LLM training data for a language spoken by less than 10 million people? Keep in mind that most of those people are probably multilingual (i.e. categorizing which language is which by person is harder), and language itself is similar to its neighbors. And then, again, terms.