Just to touch on this - Cantonese is not really mutually intelligible with modern Chinese, that's CCP propaganda. They're big on the idea that there's only one Chinese language, and there are "regional dialects" but...those dialects meet an awful lot of criteria for being a different language. It's very similar to their push to make all Chinese culture and history Han Chinese.
The mandarin spoken in Taiwan is 1:1 with that in Beijing (minus the accent) but the characters for the language are radically different, to the point where someone knowing simplified Chinese is essentially illiterate in Taipei and vice versa.