Reading the comments there's a lot of nice back and forth on this and some very not nice minimizing back and forth. I'll say what I really hate about the internet is everyone thinking they're an expert on something and have discovered the singular correct answer, so they feel the need to diminish the issue to insults and mud slinging. However, the reality is that actual experts who specialize in the field have been studying and debating and deriving non answers but general guidelines (even with stuff like language) for centuries now.
Language is an INCREDIBLY complex matter. It is something that exists not just in verbal and written speech, but so many nonverbal nodes and even modifiers for verbal like tone and inflection. For example, satire is a b*tch to translate to any audience that has a language or culture that doesn't really use satire. I mean you can't really translate something like it at all. It's interesting going to another country and realizing that your fluency and mastery of the words themselves is like maybe half of the process of actually communicating who you are (not like a background but just your personality and character) in an entirely different culture. Communication goes beyond language and language itself is complicated in that it influences culture and is also influenced by culture.
There are a lot of great examples of Japanese words that are difficult to translate while maintaining their meaning. But I'll complicate the matter more. You can perfectly translate all of them either with a dictionary translation or something that closely matches the original meaning. Like the example of "いただきます" is given. It really isn't that difficult to translate. You can "let's give grace" and more western audiences will understand that and it's in English so there's that. That's be more of a localization though. You could keep it dictionary and just say "we humbly recieve this food." That sounds nice and. Is neutral enough to not be a localization. Plus it gets the general meaning across to a western audience. But what about the original cultural meaning? What about the very different nonverbal body movements that come about from saying a single word instead of a sentence (really multiple sentences if you're giving grace properly). Even the lack of movement for a certain length of time is communication and it matters.
There is a reason why transliteration exists and people make fun of it, but there's a reason why English has so many borrowed words from other languages that are unchanged. Sometimes meaning is best conveyed by keeping a word unadulterated. Moving out for a bit, this is seen a lot in American slang already. Most slang is taken from minority groups in the States. A lot of it is African American vernacular that's a year or so old. Yet, when it makes this leap into the zeitgeist, often it's cultural meaning and origins are completely lost. This continues on when a word hits the global stage. Speaking as a Black American words can't describe the frustration in going abroad, feeling invisible or alien because of how marginalized Black cultures in countries. Like America are (both leading to many Black Americans not going abroad and media that the US creates not being reflective of how diverse the country is), and yet hearing words originally coined within African American vernacular that has lost their cultural meaning entirely. Not because the word themselves have been changed, but because how they are used and in what context has been changed. And it goes on and on. I could discuss (not even debate) language for eons based on literally a single university course and some personal experience. Imagine people who are actually in the field.
Specifically looking at this instance, slang is DIFFICULT to translate. Really, really difficult. They are practically all "in the moment" meanings that only actually exist on a cultural level. Some stick. Most have a shorter half life than... something with a really short half life (idk, I'm not a scientist). People have a hard time defining them within the language that exist (more and more don't even exist in a single language like with the rise of Spanglish in the US). You're immediately out of official dictionary translation territory. In fact the actual experts in translation are the ones in the age group who needs their own language's slang explained to them. Language is incredibly rapid in its evolution and yet also slow with those rapid developments so short lived. The best you can do is try and match meaning with some equalivalent slang word or try to create a new slang word by replicating how the slang word was formed in the other language. Japanese slang is particularly interesting because I'm going to be blunt and say that Japan is really behind on matters of global cultural diversity and how language is related to it and how deriving meaning from language and communication is something in of itself. English education in Japan isn't great. How they approach it leads to so SO much loss of meaning on both ends (as in the way Japan has normalized official translations of their own language has harmed cultural exchange for us in the west; it also very obviously harms cultural exchange from west to Japan and communication itself). That in of itself is something that says a lot of cultural and the reality of Japan (it is still a very closed off country that is still trying to navigate how to change that; calling any group a monolith comes with a great big asterisk, but Japan is a lot more homogenous than many other developed countries). It further becomes something we have to navigate as people that consume content from Japan. (I'll also say it's interesting as the country itself has a language that developed trying to balance taking Kanji from Chinese, developing hiragana as a common tongue to encourage the importance of language and written art among lower classes, and added katakana on top of that to create phonetic transliterations of borrowed and new words (like Pikachu is in Katakana)). It sounds stupid, but you'd be shocked at how much the distinction between Anime and Cartoon has on how people form thoughts and what those thoughts are regarding a certain media. I'd really encourage people to go to Japan, if they can and just talk with all the people who desperately want to speak English with you. You'll find so many roadblocks because how we tackle translation itself changes how we think about things from other cultures. I'd say Anime is seen as more of a distinct medium or style in the states as compared to cartoons. In Japan it's all just Anime. Semantics matter. They matter so so much. They arguably matter more than the words themselves. And translations garble them six ways to Sunday.
This is all to say it does "matter" (I'll retract that a little in a bit, but don't worry about that). It's not some weeb nonsense and there's nothing that grinds my gears more than people saying that. Language is complicated. I'll throw my thoughts out there and remind people that transliteration exists and is a perfectly acceptable form of enabling communication while trying to maintain original meaning. Romaji isn't Japanese (well not technically). Heck, scholars debate on the proper romanization of many Japanese words. It's a phonetic transliteration. Going back to いただきます there is a difference in using the hiragana or romaji. There's also a difference in saying 頂きます (though that's way out of my wheelhouse). Kanji itself has distinct Chinese and Japanese readings and have meanings that change based on context and usage that isn't really conveyed in a complete hiragana writing and definitely isn't in romaji.
There's no perfect answer and to the translators, yeah it realistically doesn't matter. You aren't going to please everyone in the world and honestly one route isn't even easier than the other (especially as you're dealing with two different slangs which already warp grammar rules a bit in their respective languages). Again, I like transliteration in moments like this. You can even subject a transliterated word to the grammar conventions of the language you're using it in (like there's no such thing as capitalization and possessives are handled very differently in Japanese, but that doesn't stop us for writing "Pikachu's trainer..."). But ya'll can also ignore me. Really you'll not find a way to please everyone (and upholding doing two versions isn't worth the effort). At the end of the day none of us are those scholars who specialized in this subject and have dedicated their lives to discussing these issues. The group that's translating this is doing a free service (with optional donations to support) to make media more widely available. That's fantastic no matter what. My only issue with all the comments trying to dismiss the wider issue and complex nature of language.