When I compare between visual novels that are originally developed & written in Japanese first before localization into English, often or not: the information density is different between the two. As in, the original text only comprises of like 2-3 sentences while the translation feels like reading a 4-5 line paragraph in English. Is it because translators who managed to secure the rights can’t cram all the information in a limited UI?
For example, Aksys Games is the one who does the translation while the IP holders from the source material is Otomate. They only focus on the text rather than re-doing voice acting for the English release. Lip sync is another issue since both JPN & ENG have different speech patterns, how would you even find the right casting pool in English that can deliver the same performance & emotional impact as the original JP voice actors?
This is only anecdotal, but I generally find that what I’ll call the “raw” information density difference between written Japanese and English is pretty small. There’s maybe a small advantage in Japanese.
In theory, Japanese should have a big advantage due to kanji, but once you account for having to display them at a larger size to keep them readable, plus all the other kana writing that’s still necessary, you lose almost all of it.
So why does there still seem to be so much more English text, and what do I mean by “raw” information density? Well, I’m talking about directly equivalent, often overly literal translations. To say virtually the exact same thing in both languages takes approximately the same amount of text. But Japanese in actual usage is highly contextual. You can leave out a substantial fraction of words that would be necessary in English for a grammatically correct sentence, and not only remain understandable in Japanese, but correct enough to pass muster on a written language test.
It’s entirely normal and common to omit not just subjects, but even verbs and entire clauses which the speaker assumes can be understood from context. Unfortunately a lot of this context is cultural rather than situational, and it was a real stumbling block for me for a few years. It still trips me up fairly frequently.
When someone translates this text from Japanese, it’s usually necessary to reintroduce multiple things that were left out, in order to write sentences that flow naturally in English.