It’s not valid written form of other Chinese languages, for the record. People who speak other Chinese languages learn to read and write Mandarin. Cantonese can

It’s not valid written form of other Chinese languages, for the record. People who speak other Chinese languages learn to read and write Mandarin. Cantonese can be written noticeably differently, in terms of character choice and word order. The same can be said of Shanghainese, Taiwanese, and other “dialects” for which there is extant literature, however small. Also, notably, “Classical Chinese” which is totally different from the modern variants listed above. It’s he same characters, sure, but combining in very different ways.