Mandarin is a spoken form of Chinese. So Mandarin and Cantonese, for example, share the same character set (Chinese). There's also traditional vs simplified Chinese, technically; they're similar with some differences in how they're written. Japanese also has some differences which can be confusing because a lot of application developers just use the Chinese character sets for kanji: https://heistak.github.io/your-code-displays-japanese-wrong/
One other thing about Chinese is that TV shows and movies usually have hard-coded subtitles while airing because the spoken versions of the language can be very different from one another. Including the text makes it more accessible to a wider audience regardless of what "dialect" is spoken in the show.
> So Mandarin and Cantonese, for example, share the same character set (Chinese).
This isn't really true; there are characters that are exclusive to one or the other, like 冇. The stronger political position of Mandarin means that its idiosyncratic characters are viewed as "real" while the idiosyncratic characters required by other languages aren't, but it's a fundamentally symmetric situation.
> One other thing about Chinese is that TV shows and movies usually have hard-coded subtitles while airing because the spoken versions of the language can be very different from one another.
The written versions of the language are also that different. The subtitles are in Mandarin, which everyone must learn to read.
(How common are hard-coded subtitles in modern Chinese media? They're on the older stuff, but it seems like a lot of modern shows don't bother.)
It's hard to acknowledge the massive cultural imperialism the PRC has engaged in with regards to Mandarin without getting "corrected" by people with an agenda. It's amazing how "fun facts" like "Everyone in China speaks a dialect of Chinese!" (they're vastly different languages, like how German and Italian aren't dialects of European) and "Everyone in China, no matter what dialect they speak, can pass notes!" (because everyone is forced to learn to read Mandarin no matter what language they actually speak) implicitly support that imperialism.
> [Varieties of Min] form the only branch of Chinese that cannot be directly derived from Middle Chinese.
So the divergence between Mandarin and Cantonese [neither belonging to the Min branch] could be dated back maybe 1500 years. The divergence between German and Italian is much, much older than that.
English and Swedish would make a more apt comparison than German and Italian.
This might be true if the speakers were equally distant from each other and had an equal amount of contact with each other.
I've spoken Mandarin for over 20 years, studied French and Spanish for a few years each and also learned a bit of Cantonese and a bit of Taiwanese. In my subjective experience, French and Spanish are by far the closest of any two of those languages. Cantonese and Taiwanese would be the next closest and Mandarin is considerably further from either than they are from each other.
> In my subjective experience, French and Spanish are by far the closest of any two of those languages.
This is precisely what you would expect from the divergence times.
> Cantonese and Taiwanese would be the next closest and Mandarin is considerably further from either than they are from each other.
This isn't; Taiwanese is the outgroup to the more closely related pair of Mandarin/Cantonese.
It's always possible that learning "a bit of Cantonese and a bit of Taiwanese" doesn't give you a good grasp of what's going on in Cantonese and Taiwanese.
One other thing about Chinese is that TV shows and movies usually have hard-coded subtitles while airing because the spoken versions of the language can be very different from one another. Including the text makes it more accessible to a wider audience regardless of what "dialect" is spoken in the show.