People invent new writing systems all the time. The more interesting question is why some writing systems become more successful than others.

The Chinese script is a very good fit for the Chinese language. It contains lots of phonetic hints that make sense for speakers of Chinese*. And it does not have to deal with pesky prefixes or suffixes and the like, features which other languages need to express tenses or cases or conjugation or negation. Because Chinese does not have these or expresses them with separate particles.

For languages in which these phonetic hints are less helpful or which have a different grammar from Chinese, the Chinese script is less useful. It is quite natural that in such a situation alternative or additional writing systems will appear and become successful for non-Chinese languages, while the Chinese themselves are and remain perfectly happy with their Hanzi.

You can see similar trends for the Arabic script. The script is fairly easy to learn. It leaves out a lot of phonetic information (i.e. short vowels), but because Arabic words are highly regular, this is not much of a problem for the Arabic language. It is slightly more of a problem for languages such as Turkish and Persian. And indeed Turkish has switched to the Latin alphabet a hundred years ago.

*a typical example of such phonetic information is 嗎, a question particle. It is composed of the components 口 (mouth) and 馬（horse). What is the relation between horses and questions? None really, but 馬 is pronounced "ma" and 嗎 is also pronounced "ma" (with different intonation, however).

People invent new writing systems all the time. The more interesting question is why some writing systems become more successful than others.

The Chinese script is a very good fit for the Chinese language. It contains lots of phonetic hints that make sense for speakers of Chinese*. And it does not have to deal with pesky prefixes or suffixes and the like, features which other languages need to express tenses or cases or conjugation or negation. Because Chinese does not have these or expresses them with separate particles.

For languages in which these phonetic hints are less helpful or which have a different grammar from Chinese, the Chinese script is less useful. It is quite natural that in such a situation alternative or additional writing systems will appear and become successful for non-Chinese languages, while the Chinese themselves are and remain perfectly happy with their Hanzi.

You can see similar trends for the Arabic script. The script is fairly easy to learn. It leaves out a lot of phonetic information (i.e. short vowels), but because Arabic words are highly regular, this is not much of a problem for the Arabic language. It is slightly more of a problem for languages such as Turkish and Persian. And indeed Turkish has switched to the Latin alphabet a hundred years ago.

*a typical example of such phonetic information is 嗎, a question particle. It is composed of the components 口 (mouth) and 馬（horse). What is the relation between horses and questions? None really, but 馬 is pronounced "ma" and 嗎 is also pronounced "ma" (with different intonation, however).