Japanese and Chinese in particular can compress a lot more meaning in a byte than many other languages[1]. I pick up a random article at Nikkei.com[2] and calculate number of bytes of the first paragraph, and it's only 449 bytes in UTF-8[3]. Chinese is even more efficient at this, as you can basically fit the whole news in a Tweet.

[1]: Idiomatic Yojijukugo 四字熟語 is an extreme example for this, but there's non-idiom Yojijukugo too, e.g. 日米関係 is a 12 bytes word that translates to "United States-Japan relations"

[2]: https://www.nikkei.com/article/DGXMZO46571150V20C19A6000000/

[3]: It describes how people are walking around the park in Chicago on Jun 13 to catch a rare Pokemon with a one line interview of a son of Mr. Stuart from California.

(I speak three languages: Thai, English, Japanese)