[3np]

Depending on what that sentence is, it doesn’t sound contradictory.

I considered it more as it’s own one set of characters (in the same way that kanji and Roman letters are their own)

A difference here is that while Japanese words can correctly be written as either hiragana or katakana, the idiomatic way is to mix them depending on the word (and occasionally context).

Bopomofo is its own writing system and doesn’t really get mixed with, say, pinyin.

There’s nothing to 1-to-1 map like with kana.

[JohnHaugeland]

I will trust the professional linguists on this.

Thanks for understanding. Have a good day.

[3np]

Still curious to hear that quote. Good day to you too ¯\_ (ツ)_/¯