Fundamentally, translation is a harder problem than it gets credit for. At the dictionary level, you're mostly alright, as words and concepts tend to have pretty close direct translations (though you'll often need context, as homynyms exist). A step above that, forming full statements, you run into some difficulty, due to the difficulty in translating the subtleties of word choice, as you've got a fair amount of cultural context to take into account. "Forgive me Father for I have sinned" does not carry the connotations as "Sorry, Daddy, I've been naughty". But a step up from there, translating entire texts, you need a pretty complex theory of the mind, as you need to take into account the context of the author's perspective, their interpretation of their intended audience's perspective, and your audience's perspective.

For example, my "Forgive/Sorry" joke earlier relies on the context of both you and I being somewhat aware of A) the Catholic church's process of confessional and B) the relatively modern use of "Daddy" and "naughty" with sexual connotations, which, forget language specific, is culturally specific, where the joke would break if you tried telling it to, say, a place that still used "Daddy" as perfectly normal way to address one's father, or lacked the cultural norm of sexualizing authority.

If someone was trying to translate this comment to another language, they might have to completely alter that joke in order for it to make any sense, at which point that entire last paragraph would have to change, etc. Modern AI tools have largely reached a point where the homonym problem isn't crippling them anymore, but haven't really reached much beyond that.

There's no point in offering people something they can easily make themselves. Especially when it comes to machine translation.

I often see YouTube videos with gratingly bad Norwegian titles. I believe YouTube upranks videos if the creator provides translations, and plenty of sleazy video creators just machine translate their titles to umpteen languages. Since it's a low-context translation, just one random line pasted into GT with the translator having no idea what it's about, even the best machine translation in the world will frequently produce junk.

And I have to translate the junk back into English to understand what the title was probably supposed to be. It does not help me.

(By incentivizing this junk, Google is probably poisoning its own translation training data, but that's another matter).

So two hard rules should be

1. always leave up to the user whether to use machine translation or not

2. always clearly mark translated text, especially machine translated.

Gutenberg should not waste space hosting machine translated works, unless they put a lot of effort into ensuring the quality of the translations, effort that the user couldn't easily replicate.

A lot of the human-generated public domain translations are public domain because they are pre-1920s and are pretty hard to read.

The translation of Les Misérables that is the "official" edition they sell at the gift stores if you see the musical is, to me, almost unreadable compared to modern 21st century translations.

I would think there are an enormous amount of books out there that would be improved by a modern computer translation, even with its caveats.