Why did the Chinese never adopt word spacing?
What about Rind-fleisch-eti-ket-tie-rungs-über-wa-chungs-auf-ga-ben-über-tra-gungs-ge-setz? why not adopt spacing?
And how do you think “不 矢口 亻十 么 日寸 候 ， 亻奄 口斤 言兑 言仑 土云 有 辶寸氵虑 每攵 感 字 节 白勺 言兑 氵去 ， 于是 ， 亻奄 学 会 了 扌斥 字 ， 后 来 ， 亻奄 米青 礻申 分 歹刂 了 。”
To be serious, the main purpose of spacing is to disambiguate words. However, in Chinese the meaning of a sentence is heavily depended on the context, rather than the spaces between the characters, eg:
今天真热。 (It is very hot today)
小孩很天真。 (kids are very innocent)
Everyone exactly knows the meaning of the above two sentences though each has a entirely different form of “天真”, thus it is superfluous to introduce spacing like:
今天 真 热。(today very hot)
小孩 很 天真。(kids very innocent)
It looks quite ugly/silly and will significantly reduce reading efficiency, just like the 2nd example I highlighted.
In fact, the Chinese Communist Party government once would like to promote spacing between Chinese characters as part of their ambitious “Characters reform”, but they failed like an idiot in the end. Henceforth, Nobody would mention it.