There are too many cases where people have uploaded chapters with very terrible translations, from very obvious google translations to even removing lines or making things up when the translator probably didn't know what the line meant. this can have serious consequences and can do a lot more harm than help. While the consequences are far worse when bad translations are of things people said (for example there are a lot of vtuber drama cases that happened because a bad translator with a big following posted a clip that caused huge misunderstandings. one example is the rushia "end your stream" controversy) because you'd be putting words in their mouth, bad translations of an author's works can make their works seem poorly written or worse, make them sound like they support controversial topics when they don't. East Asian languages, especially Japanese and Chinese (I personally cannot understand Korean so I can't speak for that language but i imagine it would be similar) rely on a lot of reading between the lines that is very easily missed by machine translators and hard to pick up on if you're not used to the language.
Let's say there was a line in a manga that said 彼女は料理できる. An inexperienced translator may translate that line as "girls can cook". congrats, you made whoever said that line sound like a mysogynist. But let's say the background context is that a group of friends is on a trip and person A is trying to reassure person B who is worried what they're gonna do for food since the other party members are bad at cooking. Then the "girl" part of the line wasn't talking about girls in general, but one specific girl. The correct translation would be "THAT girl can cook". do not bank on the comments section to hopefully let that fly because (especially on this site) people go nuts over the smallest things. imagine mistranslating a chapter that makes a character look like they're forcing another. people here DO NOT take r*pe lightly (as they should but the way some ppl act sometimes goes out of line). you do not want people to take these to social media and tell people not to support the author because they're misogynistic or worse, send hate and death threats to the author for no reason. people on the english side of sns throw around "kys" so easily and often that (while it's a serious thing and you shouldn't say it lightly) people tend not to take it to heart. Unfortunately that's not how it is in east asian culture and they will likely take it to heart, very confused as to what they did to deserve it. yes there are nasty trolls, but they stay mostly in their forums and don't bring the kind of language used there into other more "normal" spaces (for the lack of a better word atm).
another real life example was a tweet someone replied to YD (author of blind play) with poorly translated DMs and people went insane thinking YD was trying to hire a hitman to get the uploader (wtf guys, have you been reading too many comics). yes they were trying to get the uploaders personal information (which is still bad) but im 99% sure it's not so they can send a hitman.
If you aren't decently fluent in the language you're translating from and constantly have to check machine translations for whole sentences, you should not be translating. Learning is a process that's long and tiresome, I get that, and you don't have to have fancy education like JPLT to be fluent enough to translate (in fact there are many cases where people passed N1 level but their actual capabilities aren't at a level they can interact with natives or go to Japan without problems). but if you're not ready, you need to accept that. That's why more reputable scanlation groups like death toll scans have small tests for potential recruits in each category (translating, cleaning etc.) so that their work meets a certain standard and level of accuracy. It's fine to do it for your own personal learning experience, but do not post those translations online if your skill isn't there yet. If you want to post SOMETHING, raws are much better than poorly translated english. people can throw it into google translate (though deepl and papago are much better, but not perfect) themselves
i wrote this all out so that i had a base to copy and paste parts of it under manga with bad translations when i correct them but it's something important that anyone planning to translate should know so do take a read if you're a new translator or thinking of translating.
