Like manga, I hate it when they, for example, transliterate さん as -san, when there is an “equivalent” word for it, like Mr. but would it carry the same connotation as the source material? I cringe when I buy translated versions of Japanese literature due to this (which is why I stick to the source material), it just… does not sit well, I mean instead of writing -sensei, -senpai, or -sama there are “equivalents” in English for those but the catch is that would it work well upon translation?
I’m sure that’s part of it but the worse offender imo is that Japanese expresses tone differently (with particles and context for instance). The biggest issue I have with JP>EN translations is that a sentence that could be playful and excited in the original will read like an 80 year old scientist who’s never played outside’s work journal.