as someone who’s Dutch, the way this all works in English is so absurd

Yeah but don’t you say Japan instead of Nihon/Nippon? Every language does this to a certain extent.

Just remember that “no” is the particle that indicates possession, so you need to show what it’s possessing if you use it.

Sore can be used as a subject or object directly:

それを説明して下さい。
Explain that please.

Compared to:

その話を説明して下さい。
Explain that conversation please.

Using “no” to show possession can be used without indicating the possessed word with regular nouns, but not the kono/sono/ano words.

家のドアは大きい。
The house’s door is big.
家のは大きい。
The house’s is big.

In Grench

Is that the Grinch’s native language?

Or any country really. I’d be curious to see if a chart of languages ranked on how many countries’ endonyms are also the same word in that language. But there’s definitely no language that doesn’t have exonyms.

https://en.wikipedia.org/wiki/Endonym_and_exonym