I recently befriended a Japanese guy, who’s an aspiring(?) writer / novelist.
When it comes to novels, they have a lot of these “words that no one uses” in them - words that are more expressive and nuanced, than the words that appear in daily conversations. Similar to English literature, there’s a lot of words mainly used in writing only. BUT the difference is, English natives seem to generally still know and understand the “written language” -words, whereas Japanese people may not*.
To elaborate, this guy said that because he needs to keep using these more nuanced words in order to keep his skills from getting rusty and affecting his writing, he’s has also become able to somehow evaluate the smarts (quoting his own choice of words here) of the person he’s talking to. By this I mean, that the less educated and less books one reads, the amount of difficult words they know also becomes smaller (should be obvious).
When this guy notices that the person he’s speaking to is having difficulty understanding his words, he has to adjust to simpler Japanese. If the person is “smart” (again, only using his words here), he can talk freely and know that he’s being understood. I find it at the same time fascinating… hmm… phenomena, so to speak, as well as a shame - conversations could have the potential to become much more vivid than they are now, but still everyone seems pretty much content with the extent they’re able to express themselves with the regular vocab (then again, Japanese people and unrestrained self-expression…? :3 )
Hence you may run into people who tell you “no one uses these words”, when they are unfamiliar with the vocab. If they had more info, they could tell you also “this is mainly used in writing” or “That’s actually a legal term… not everyone knows it” etc. (Please note: I’m not saying the people who tell you about words that aren’t used are stupid! Just that even if they’re Japanese, they might not be the equivalent of an Oxford dictionary)
I see @tsukuba has come across a related situation:
*My 1-on-1 Japanese “teacher” said she has to use a Japanese-Japanese dictionary when she’s reading novels. She said it’s somehow fun to see different, nuanced ways of expression being used, since she doesn’t know them herself.