"Bopomofo" is also without a doubt my favorite Chinese word to say out loud.
For instance there is the popular anime titled “Sailor Moon” which is written in Katakana like セーラームーン and stranger still the second season is called “Sailor Moon R” (I think for “return”) and is written セーラームーン R.
My understanding is that Bopomofo never caught on particularly well
https://en.wikipedia.org/wiki/Bopomofo
it is still used in education in Taiwan but in Taiwan, the mainland and the rest of the sinosphere people who want to spell out Chinese words are more likely to use Pinyin
If Chinese folks want to write Churchill, they might write:
A) Churchill
B) 丘吉尔
But they will never write:
C) Qiūjí'ěr (the pinyin for B)
I've never seen an adult Chinese use pinyin for anything other than typing (as an input method for Chinese characters).
Earlier, e.g. in the books written a few hundred years ago, hiragana was used like today, i.e. inlined with kanji, for writing verb and adjective terminations or various grammatical particles, but katakana was used as furigana, for showing the pronunciation of the more seldom used or ambiguous kanji, especially when the Chinese reading was used for those kanji.
The use of katakana for the writing of foreign words has developed from its use for writing the approximate pronunciation of Chinese words.
The writing reform enforced after WWII has introduced significant changes in the use of hiragana and in the correspondences between kanji and hiragana (and also many kanji have been substituted with simplified variants), so reading a pre-war book can be challenging for someone familiar only with modern Japanese.
The few English ex-pats that I knew used the 搜狗 software which defaults to pinyin I think.
I mostly used pinyin on my laptop and bopomofo on my phone (old model that didn't support pinyin) which was mildly annoying. I constantly got it confused with my Japanese since I also read hiragana/katakana and some of the symbols are highly similar.
This is just my personal experience, but I think the big change in the past 15 years isn't Bopomofo -> Pinyin, but rather Wade Giles -> Pinyin. Bopomofo seems equally prevalent, but the Wade Giles romanizations on street signs have begin to get replaced with Pinyin for the sake of non-native speakers who are almost certainly more familiar with Pinyin than WG.
