I think the more likely explanation is that Apple has a small team supporting all of the world's languages, mostly focusing on widely-spoken ones, while Sogou has a small team focusing on languages widely spoken in China, so their Cantonese support is better.
And somehow Apple Arcade still not available in HK and Mainland China?
Edit: Actually this brings back memory. About twenty+ years ago I made an English to Cantonese Translation with Romanization Input Method on Windows and later on Mac using VanillaInput / OpenVanilla so I could use it for IRC and ICQ. At the time voice recognition of anything was sci-fi stuff. Dragon speech recognition sucks no matter how much training time you give it. Twenty years later we are close to real time on devices speech recognition.
Perhaps the difference is one of degree rather than an absolute difference
They are doing it. Sources: few HK friends that were really worried about the future of their language and culture. And this was before the security law.
Last time I checked, less than half of the population in Guangzhou knew how to speak Cantonese.
But what I was actually talking about were Huizhou, Heyuan, Meizhou etc. Basically, Cantonese extends as far east as Hong Kong and further east of that is marked as Hakka territory in the Language Atlas of China https://upload.wikimedia.org/wikipedia/commons/a/a9/Map_of_s... Meixian Hakka from Meizhou in particular has a prominent position within Hakka culture. https://en.wikipedia.org/wiki/Meixian_dialect
But they can't buy a textbook on their first language because the official policy is that everything that is not Mandarin is a «dialect», and dialects can't be studied (as in «are impossible to study due to not deserving to be studied»), therefore there is no need for textbooks.
Have you tried to buy one?
I have had no problem buying Cantonese teaching materials, including the Robert Bauer's comprehensive Cantonese dictionary, Victoria Yip's Cantonese grammar book and a quite a few more obscure ones from Western online book sellers.
> Shenzhen
Shenzhen used to speak with Cantonese. All the way back from 70s to 90s after it was a fishing village. Everybody knew / learn how to speak with Cantonese because of Guangdong and Hong Kong.
Like I said above in another comment, most of the teens who were born from a Cantonese language family now dont speak the language anymore.
If you wish to dispute my comment, please provide anecdata or a peer reviewed study or poll/survey that supports your view.
Also, you wrote <<All the way back from 70s to 90s after it was a fishing village>> This statement makes no sense. Deng Xiaopeng did not 'open' Shenzhen until 1979. It was still a small, regional city well into the 1980s. It wasn't a multi-million person metropolis until the mid-1990s.
Should have written 80s to 90s. Generally speaking we talk about Fishing village as before all the manufacturing investment going up to China. That was when the whole manufacturing industry in HK moved up north, where north meant across the border to Shenzhen.