Totally agree, I don't think em dashes are a particularly useful AI tell unless they're used in a weird way. Left to my own devices (as a native English speaker who likes em dashes and parentheticals), I often end up with at least one em dash every other paragraph, if not more frequently.

On another note, it may be useful to you to know that in most English dialects, referring to a person solely by their nationality (e.g., when you wrote "as a Chinese") is considered rude or uncouth, and it may mark your speech/writing as non-native. It is generally preferable to use nationalities as adjective rather than nouns (e.g., "as a Chinese person"). The two main exceptions are when employing metonymy, such as when referring to a nation's government colloquially (e.g., "the Chinese will attend the upcoming UN summit") or when using the nationality to indicate broad trends among the population of the nation (e.g., "the Chinese sure know how to cook!"). I hope this is considered a helpful interjection rather than an unwelcome one, but if not, I apologize!