Zhuyin was created on the Mainland during the ROC era, and brought to Taiwan after the Japanese surrender, where it is now the most prominent phonetic system. P

Zhuyin was created on the Mainland during the ROC era, and brought to Taiwan after the Japanese surrender, where it is now the most prominent phonetic system. Prior to the KMT retreat to Taiwan, Mandarin was not widely spoken here. Before Japan colonized Taiwan, Taiwanese language (Minnan) was usually written using Latin characters with diacritics. During the Japanese colonial era, they attempted to introduce Taiwanese kana. I don't think usage has survived to present day, but I have met a few old people who can only speak Japanese and Taiwanese, but not Mandarin. Today Taiwanese is mostly a spoken language, but you can find it written. Sometimes it's a mixture of hanzi and Latin characters to supplement missing characters. I've heard that there is also an adapted Zhuyin used to write Taiwanese, but I've never seen an example of it. tl;dr Zhuyin and and Taiwanese kana were developed during approximately the same time, but separately, and for separate languages.