I have used "--" as a lazy-man's emdash for decades at this point. Once I heard that people started assuming text that uses emdashes was written by an LLM I got worried that people were going to think that
I'm an LLM, but then I realized the LLMs use the real unicode emdash character, while I just use two regular ASCII-zone hyphens. Whew.
(Also I just learned that ASCII 0x2d/unicode U+002D is more properly called a "hyphen" [well, "HYPHEN-MINUS"], not a "dash".)