[xiaoma]

As a long-time speaker of Mandarin who is learning Taiwanese Hokkien, I can't really agree with that. There are many characters and even words that are written the same way in each language, but there are many, many more which are not. Aside from the characters used specifically for Hokkien, there are numerous phrases which mean one thing in one language and another in the other. For example, 失禮 would mean lacking in manners in Mandarin, but it means sorry in Hokkien. Hokkien text, even when rendered in characters, is largely incomprehensible to Mandarin speakers.

[tokenadult]

Hokkien text, even when rendered in characters, is largely incomprehensible to Mandarin speakers.

I can confirm the truth of this example, which is one of the examples I had in mind in some of my earlier comments.