Do we intentionally translate ancient stuff and languages to sound old timey as an artistic choice, or is there some other reason?

I'll focus on Latin because I don't know how much this applies to Greek, Sumerian, Sanskrit, Akkadian etc.

Lots of translators focus too much on individual words, and miss the text. So when handling Latin they

spam less common synonyms (specially Latin borrowings)
try to follow Latin syntax too closely into English
use large sentences full of appositions

Less common words, fancy syntax, large sentences? That makes the text sound old timey.

I'll give you a practical example with Caesar's De Bello Gallico. Granted, the translation is from the 1800s, but even for those times it's convoluted:

[Original] Gallia est omnis divisa in partes tres, quarum unam incolunt Belgae, aliam Aquitani, tertiam qui ipsorum lingua Celtae, nostra Galli appellantur.

[Bohn and McDevitte] All Gaul is divided into three parts, one of which the Belgae inhabit, the Aquitani another, those who in their own language are called Celts, in our Gauls, the third.

There's almost a 1:1 word correspondence. With the following exceptions:

"the" - because not using it in English makes the text sound broken
"in", "of" - because English demands prepositions more frequently than Latin
"their own" - because English lacks a 1-word equivalent for "ipsorum"

For reference here's how I'd translate the same excerpt:

Gaul is split into three parts. One is inhabited by the Belgae; another, by the Aquitani; the third one, by those who call themselves "Celts", and that we call "Gauls".

I'm not a good translator, mind you. And I'm myself fairly pedantic. Even then, I believe that it delivers the point better - it's streamlined, using concise and clear language, like a military commentary written by a general is supposed to be. But it is not a 1:1 like those guys obsess over.

Wow! Awesome explanation! Thanks!
Good translation is as much an art as a science, even between modern languages. I wish more translations focused on intent rather than a literal 1:1
That's a pretty good example. If you get into Bible translation you'll find there's a massive world of stuffingy* about different translation approaches. Because as well as having what I presume is by far the largest and longest collective scholarship to study and translate, plus textual criticism over multiple ancient copies, plus emotional hand-me-downs (people liking the KJV because it's what they grew up with), it's also considered by many translators to be the holy word of God, so "I think my translation's a bit clearer than yours" becomes "therefore yours falsely represents the very Words of God and may deceive people away from following the Truth!!!!"

Fascinating stuff, though.

*I meant to write 'argument' but gboard thought 'stuffingy' is better.
- Yup. And the Bible is a notorious example of that, since a lot of versions are retranslations from Koine Greek, Aramaic and Old Hebrew into Latin into modern languages. And even if the Latin Vulgata was well made*, you're bound to have the process happening twice.
  
  *It could be worse. One of the reasons why Jerome worked on the Vulgata was because he didn't like the Greek translations of Hebrew texts. Without that, people would be translating into modern languages the Latin translation of the Greek translation of Hebrew texts. Yup.
Thanks! This is the closest thing I've seen on Lemmy to an r/AskHistorians thread, wish we had more of that

I can think of a few reasons a translator might choose to do that:

The original author was using language that was old-fashioned in their time (e.g., a medieval Latin writer imitating Cicero, or a Hellenistic Greek writer imitating Thucydides)
The work in question had its greatest historical impact long after its original composition, so its language would have seemed archaic to the relevant readers (e.g., the Vedas, Avestas or Analects)
The translator is trying to maintain consistency with canonical translations of related works done long ago (e.g., translating early Christian writings in the King James style)
The translator wants to create a general sense of cultural distance, if placing the culture of the original work in a modern context would be misleading

Tacking on: as far as translation of ancient texts is concerned there is also a selection bias. It is far more likely that an important formal document endured the times than some every day scribble. Of course a political treaty is crafted, conserved and replicated more carefully than a note someone left for their neighbor. Both the skill of writing and the materials required were much rarer and access more prevalent among the upper classes. Finally important formal documents are more likely to be translated precisely because they are important. Imagine that in 2000 years from now you would be one of the few scholars capable of translating English. You would be much more to likely to study and translate the declaration of independence than some mundane Twitter post.

That might have been the style it was translated at the time and no one updated it.

I think all the other comments have some validity. In particular, the most famous or readily available (and certainly the most readily available for free) translations often were done by a "classy Englishman from the 1800s." In the case of Latin and Greek, sometimes it was the 1700s.

Another point not yet raised is that the languages will simply convey different things in a single word or phrase, and if you want to maintain that meaning, sometimes tone will take a backseat to linguistic data. Good translations will provide context for what the tone and intended audience would be, as far as we can tell, and also for the translator's methodologies and biases.

This introduction to a modern translation of Cicero gives, I think, a fairly decent rundown of the difficulties inherent in this process. See page 7; it is a Google Books link, fair warning.

I know from Historia Civilis that at least part of it is with the intention of preventing the masses from knowing that oh so noble and dignified Marc Anthony could swear and curse like a sailor with chronic blue balls in his letters to Octavian

Literally one of his letters is complaining about why Octavian is making a stink about him fucking Cleopatra when he's already plowed his way through Rome's finest bachelorettes, who he lists by name!

A lot of old stuff doesn't translate cleanly, even between two modern, similar languages.

Imagine if the only German you knew of was from an 80 year old German-English dictionary that you had to use to translate a news article written in German last week. Newer words are completely absent, places have changed names, good luck pronouncing anything correctly, and idioms, slang, and many scientific, political, and cultural reference are completely indecipherable. Proper nouns (ie names) will be somewhat challenging, especially names invented in the last few decades.

My aunt moved from Germany to France in the 50s or 60s or so. When she speaks German she doesn't have a French accent or anything but it still sounds slightly off because her language stopped evolving. It's eerie and cute.
- My grandmother took me to her birthplace in Denmark and kept saying she couldn't speak Danish with the locals, despite having spoken Danish with her family in America semi-regularly. I never thought it was because her vocabulary and accent was stuck in 1940s and she didn't feel confident speaking that way.

I imagine with a lot of ancient languages there's about 3 people capable of translating it and they're all university professors in ancient history, who write like that normally.

Language changes over time so they're probably trying to make the translation sound accurate to the time period it was written in I would guess. The tone of the text is sometimes as important as the actual content

I want them to translate things into zoomer english.

"Went to the tavern today, the lukewarm beer was straight bussin fr."
- No cap, bro.
- You should try some Bible paraphrases. (They're usually not called 'translations' once they have that much artistic licence.)
  
  "The Street Bible", I think was a UK paraphrase into urban slang in the ... late 90s? early 2000s? (Yeah, I could Google, but you could to and I'm lazy.)
  
  The most fun I found one time was a New Testament translation into Scots English. Looks gibberish (to me) but if you read it and imagine a heavy Scots accent, it all starts to make sense again as English.

Do you have an example?

Yeah, whatdya mean?
I don't have direct examples because I suck at googling, but what I saw that made me think of this was an ancient Greek philosopher insulting another, presumably in a rude tone, but still translated to look super polite and old timey. The explanations people have given here have really shed a lot of light for me on why that is though, so it makes sense to me now.

Could you give some examples of what you mean?

I tried to find examples but turns out I'm really bad at googling. Quotes of ancient Greek philosophers is one example though. Surely not all of them spoke formally, and I've heard some even spoke rather rudely, and yet when they're translated they're still translated into really formal, old timey language. There's been some nice explanations here of why that is though, so I understand a lot better.

If we're talking about English, there were different kinds of English which were spoken (Old English, Middle English, Early Modern English, and Modern English. And no, Old English doesn't just mean English that sounds 'old'. It was an early variety of English that was spoken from the 5th/7th century to 1066). All of them had their own phonology, morphology and syntax. In short, they followed their own linguistic rules and conventions. The way they sounded wasn't just randomly made up. To find out more, look up the varieties of English I mentioned or take a look at this Wikipedia article about Historical linguistics.